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T Kataoka

Publications and source records attributed to T Kataoka.

At least 19 recordsLinked to original sources
PubMed2005

Prognostic factors and a scoring system for patients with skeletal metastasis.

Between 1992 and 1999, we treated 350 patients with skeletal metastases. A multivariable analysis of the patients was conducted using the Cox proportional hazards model. We identified five significant prognostic factors for survival, namely, the site of the primary lesion, the performance status (Eastern Cooperative Oncology Group status 3 or 4), the presence of visceral or cerebral metastases, any previous chemotherapy, and multiple skeletal metastases. The score for each significant factor was derived from the corresponding estimated regression coefficients (natural logarithm of the hazard ratio). The prognostic score was calculated by adding all the scores for individual factors. The rate of survival was 31% at six months and 11% at one year for the patients with a prognostic score of 6 or more. By contrast, patients with a prognostic score of 2 or less had a rate of survival of 98% at six months and 89% at one year. This scoring system can be used to determine the optimal treatment for patients with pathological fractures or epidural compression.

Adolescent↗
PubMed2004

Modifications and intracellular trafficking of FADD/MORT1 and caspase-8 after stimulation of T lymphocytes.

The adaptor protein FADD/MORT1 is essential for apoptosis induced by 'death receptors', such as Fas (APO-1/CD95), mediating aggregation and autocatalytic activation of caspase-8. Perhaps surprisingly, FADD and caspase-8 are also critical for mitogen-induced proliferation of T lymphocytes. We generated novel monoclonal antibodies specific for mouse FADD and caspase-8 to investigate whether cellular responses, apoptosis or proliferation, might be explained by differences in post-translational modification and subcellular localisation of these proteins. During both apoptosis signalling and mitogenic activation, FADD and caspase-8 aggregated in multiprotein complexes and formed caps at the plasma membrane but they did not colocalise with lipid rafts. Interestingly, mitogenic stimulation, but not Fas ligation, induced a unique post-translational modification of FADD. These different modifications may determine whether FADD and caspase-8 induce cell death or proliferation.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Implications of plasma concentrations of adiponectin in patients with coronary artery disease.

OBJECTIVE: To investigate whether concentrations of plasma adiponectin constitute a significant coronary risk factor, with particular focus on the relation between plasma concentrations of adiponectin and the development of acute coronary syndrome (ACS). SUBJECTS AND METHODS: Plasma concentrations of adiponectin were measured in 123 patients with coronary artery disease (CAD) and in 17 control participants. Patients were divided into three groups according to condition type: acute myocardial infarction (AMI) group (n = 59), unstable angina pectoris (UAP) group (n = 28), and stable angina pectoris (SAP) group (n = 36). RESULTS: Plasma concentrations of adiponectin correlated negatively with body mass index (r = -0.18, p < 0.05), serum triglyceride (r = -0.25, p < 0.01), and fasting glucose concentrations (r = -0.21, p < 0.05), but correlated positively with age (r = 0.26, p < 0.01), high density lipoprotein cholesterol concentrations (r = 0.35, p < 0.01), and low density lipoprotein particle size (r = 0.37, p < 0.01). Plasma concentrations of adiponectin in patients with ACS, in both the AMI and UAP groups, were significantly lower than those in patients with SAP and in the control group (ACS, 6.5 (3.0) microg/ml; SAP, 11.3 (5.9) micro g/ml; control 12.8 (4.3) microg/ml; p < 0.01). Additionally, plasma concentrations of adiponectin in patients with CAD (7.9 (4.6) microg/ml, p < 0.01) were significantly lower than in the control group. There were, however, no significant differences between patients with SAP and the control group (p = 0.36). Multiple logistic regression analysis showed that smoking, fasting glucose concentration, and low log adiponectin concentration correlated independently with the development of an ACS. CONCLUSIONS: The findings suggest that measurement of plasma concentrations of adiponectin may be of use for assessing the risk of CAD and may be related to the development of ACS.

Adiponectin↗
PubMed2003

Equation-of-state measurements of polyimide at pressures up to 5.8 TPa using low-density foam with laser-driven shock waves.

The laser-driven equation-of-state (EOS) experiments for polyimide are presented. The experiments were performed with emission measurements from the rear sides of shocked targets at up to a laser intensity of 10(14) W/cm(2) or higher with 351 nm wavelength and 2.5 ns duration. Polyimide Hugoniot data were obtained up to 0.6 TPa with good accuracy. Applying low-density foam ablator to the EOS unknown material, we also obtained the data at a highest pressure of 5.8 TPa in the nonmetal materials. Those data were in agreement with the theoretical curves.

Journal Article↗
PubMed2002

[Redo coronary artery bypass grafting using the patent left internal thoracic artery graft as an in flow with composite internal thoracic artery Y grafting; report of a case].

In redo coronary artery bypass grafting (CABG), graft selection and revascularization methods are major problems. We experienced a redo-CABG with occluded previous vein grafts. These grafts were to the circumflex artery and right coronary artery. We conducted operation using cardiopulmonary bypass. We at this operation, chose right internal thoracic artery (RITA) as a conduit and anastomosed it to the side of functioning left internal thoracic artery (LITA) graft, and then diogonal branch, posterolateral branch, and atrioventricular branch were revascularized with the RITA. Post operative course was uneventful. Internal thoracic artery (ITA) is superior to vein graft and other arterial graft as to long term patency. We believe composite Y graft with the use of bilateral ITA can be one of the revascularization strategy in redo CABG.

Coronary Artery Bypass↗
PubMed2002

Selection of surgical methods for infected infrarenal abdominal aortic aneurysms.

BACKGROUND: There is no standard treatment for patients with infected abdominal aortic aneurysm (AAA). To determine the basis for selection of a surgical method, we reviewed our experiences with all patients who underwent surgery for infected infrarenal AAA. METHODS: Between 1993 and 2000, 6 patients with infected infrarenal AAA underwent surgery. Extra-anatomic bypass grafting was performed in 2 of 3 patients with infection extending into the retroperitoneum. In situ grafting was performed in 3 patients with localized infection and in 1 patient with extended infection. RESULTS: Severe peritonitis occurred in 2 patients with extended infection in the early postoperative phase. One patient, who had undergone in situ grafting, died of sepsis. The other patient, who had undergone extra-anatomic bypass grafting, was treated by continuous irrigation with an electrolyzed strong acid aqueous solution (ESAAS). He recovered gradually and was discharged. After a follow-up period with a mean of 40 months (range: 17-102 months), all 5 patients who survived surgery are alive and asymptomatic. CONCLUSIONS: It was suggested that the method used for revascularization should be selected based on the degree of diffusion of infection. For a patient with extended infection, postoperative continuous irrigation with ESAAS appears to be effective in eradicating retroperitoneal infection.

Aged↗
PubMed2001

Identification and characterization of RA-GEF-2, a Rap guanine nucleotide exchange factor that serves as a downstream target of M-Ras.

The Ras family small GTPase Rap is regulated by an array of specific guanine nucleotide exchange factors (GEFs) in response to upstream stimuli. RA-GEF-1 was identified as a novel Rap GEF, which possesses a Ras/Rap1-associating (RA) domain. Here we report a protein closely related to RA-GEF-1, named RA-GEF-2. Like RA-GEF-1, a putative cyclic nucleotide monophosphate-binding domain, a Ras exchanger motif, a PSD-95/DlgA/ZO-1 domain, and an RA domain in addition to the GEF catalytic domain are found in RA-GEF-2. However, RA-GEF-2 displays a different tissue distribution profile from that of RA-GEF-1. RA-GEF-2 stimulates guanine nucleotide exchange of both Rap1 and Rap2, but not Ha-Ras. The RA domain of RA-GEF-2 binds to M-Ras in a GTP-dependent manner, but not to other Ras family GTPases tested, including Ha-Ras, N-Ras, Rap1A, Rap2A, R-Ras, RalA, Rin, Rit, and Rheb, in contrast to the RA domain of RA-GEF-1, which specifically binds to Rap1. In accordance with this, RA-GEF-2 colocalizes with activated M-Ras in the plasma membrane in COS-7 cells, suggesting a role of RA-GEF-2 in the regulation of Rap1 and Rap2, particularly in the plasma membrane. In fact, an increase in the level of the GTP-bound form of plasma membrane-located Rap1 was observed when coexpressed with RA-GEF-2 and activated M-Ras. Thus, RA-GEF-2 acts as a GEF for Rap1 and Rap2 downstream of M-Ras in the plasma membrane, whereas RA-GEF-1 exerts Rap GEF function in perinuclear compartments including the Golgi apparatus.

Amino Acid Sequence↗
PubMed2001

Epidermal growth factor stimulation of the ACK1/Dbl pathway in a Cdc42 and Grb2-dependent manner.

The tyrosine kinase ACK1 phosphorylates and activates the guanine nucleotide exchange factor Dbl, which in turn directs the Rho family GTP-binding proteins. However, the regulatory mechanism of ACK1/Dbl signaling in response to extracellular stimuli remains poorly understood. Here we describe that epidermal growth factor stimulates the ACK1/Dbl pathway, leading to actin cytoskeletal rearrangements. The role of the two ACK1-binding proteins Cdc42 and Grb2 was assessed by overexpression of the Cdc42/Rac interactive binding domain and a dominant-negative Grb2 mutant, respectively. Specific inhibition of the interaction of ACK1 with Cdc42 or Grb2 by the use of these constructs diminished tyrosine phosphorylation of both ACK1 and Dbl in response to EGF. Therefore, the activation of ACK1 and subsequent downstream signaling require both Cdc42-dependent and Grb2-dependent processes within the cell. In addition, we show that EGF transiently induces formation of the focal complex and stress fibers when ACK1 was ectopically expressed. The induction of these structures was totally sensitive to the action of botulinum toxin C from Clostridium botulinum, suggesting a pivotal role of Rho. These results provide evidence that ACK1 acts as a mediator of EGF signals to Rho family GTP-binding proteins through phosphorylation and activation of GEFs such as Dbl.

Actins↗
PubMed2001

Role of the CDC25 homology domain of phospholipase Cepsilon in amplification of Rap1-dependent signaling.

Phospholipase Cepsilon (PLCepsilon) is a novel class of phosphoinositide-specific PLC characterized by possession of CDC25 homology and Ras/Rap1-associating domains. We and others have shown that human PLCepsilon is translocated from the cytoplasm to the plasma membrane and activated by direct association with Ras at its Ras/Rap1-associating domain. In addition, translocation to the perinuclear region was induced upon association with Rap1.GTP. However, the function of the CDC25 homology domain remains to be clarified. Here we show that the CDC25 homology domain of PLCepsilon functions as a guanine nucleotide exchange factor for Rap1 but not for any other Ras family GTPases examined including Rap2 and Ha-Ras. Consistent with this, coexpression of full-length PLCepsilon or its N-terminal fragment carrying the CDC25 homology domain causes an increase of the intracellular level of Rap1.GTP. Concurrently, stimulation of the downstream kinases B-Raf and extracellular signal-regulated kinase is observed, whereas the intracellular level of Ras.GTP and Raf-1 kinase activity are unaffected. In wild-type Rap1-overexpressing cells, epidermal growth factor induces translocation of PLCepsilon to the perinuclear compartments such as the Golgi apparatus, which is sustained for at least 20 min. In contrast, PLCepsilon lacking the CDC25 domain translocates to the perinuclear compartments only transiently. Further, the formation of Rap1.GTP upon epidermal growth factor stimulation exhibits a prolonged time course in cells expressing full-length PLCepsilon compared with those expressing PLCepsilon lacking the CDC25 homology domain. These results suggest a pivotal role of the CDC25 homology domain in amplifying Rap1-dependent signal transduction, including the activation of PLCepsilon itself, at specific subcellular locations such as the Golgi apparatus.

Animals↗
PubMed2001

RA-GEF-1, a guanine nucleotide exchange factor for Rap1, is activated by translocation induced by association with Rap1*GTP and enhances Rap1-dependent B-Raf activation.

We previously identified RA-GEF-1, a novel guanine nucleotide exchange factor (GEF) for Rap1 with the ability to associate with Rap1.GTP at its Ras/Rap1-associating (RA) domain. Because it possesses a PSD-95/DlgA/ZO-1 (PDZ) domain, it was also named PDZ-GEF. In this report, we have examined the role of the RA domain of this protein in Rap1-mediated cellular responses. A mutant of RA-GEF-1 (RA-GEF-1DeltaRA) carrying a 21-residue deletion at its RA domain fully retains the in vitro GEF activity toward Rap1 but completely loses the Rap1 binding activity. In contrast, RA-GEF-1DeltaRA, expressed in COS-7 cells, exhibits a 3-fold reduction in its in vivo GEF activity toward Rap1 compared with wild-type RA-GEF-1 as examined by the Rap1 pull-down assay. Correspondingly, when coexpressed with wild-type Rap1, RA-GEF-1DeltaRA is unable to further activate B-Raf, whereas RA-GEF-1 stimulates B-Raf as efficiently as activated Rap1. Consistent with these observations, coexpression of activated Rap1 induces translocation of RA-GEF-1, which is otherwise located in the cytoplasm, to the perinuclear compartment, where Rap1 is also predominantly localized. This localization almost coincides with that of the Golgi apparatus, which was detected by anti-trans-Golgi-network 38 antibody. RA-GEF-1DeltaRA fails to show the translocation. These results indicate that RA-GEF-1 defines a novel category of GEF that is translocated to a particular subcellular compartment by association with the GTP-bound form of a small GTPase and catalyzes activation of the GDP-bound form present in the compartment, thereby causing an amplification of cellular responses induced by the small GTPase.

Animals↗
PubMed2001

Bcl-rambo, a novel Bcl-2 homologue that induces apoptosis via its unique C-terminal extension.

The Bcl-2 family of proteins plays a central regulatory role in apoptosis. We have identified a novel, widely expressed Bcl-2 member which we have named Bcl-rambo. Bcl-rambo shows overall structural homology to the anti-apoptotic Bcl-2 members containing conserved Bcl-2 homology (BH) motifs 1, 2, 3, and 4. Unlike Bcl-2, however, the C-terminal membrane anchor region is preceded by a unique 250 amino acid insertion containing two tandem repeats. No interaction of Bcl-rambo with either anti-apoptotic (Bcl-2, Bcl-x(L), Bcl-w, A1, MCL-1, E1B-19K, and BHRF1) or pro-apoptotic (Bax, Bak, Bik, Bid, Bim, and Bad) members of the Bcl-2 family was observed. In mammalian cells, Bcl-rambo was localized to mitochondria, and its overexpression induces apoptosis that is specifically blocked by the caspase inhibitors, IAPs, whereas inhibitors controlling upstream events of either the 'death receptor' (FLIP, FADD-DN) or the 'mitochondrial' pro-apoptotic pathway (Bcl-x(L)) had no effect. Surprisingly, the Bcl-rambo cell death activity was induced by its membrane-anchored C-terminal domain and not by the Bcl-2 homology region. Thus, Bcl-rambo constitutes a novel type of pro-apoptotic Bcl-2 member that triggers cell death independently of its BH motifs.

Amino Acid Motifs↗
PubMed2001

Synthesis and biological evaluation of nonylprodigiosin and macrocyclic prodigiosin analogues.

Nonylprodigiosin (4) and various of its analogues have been prepared by Suzuki cross-coupling reactions of a well accessible pyrrolyl triflate with (hetero)aryl boronic acid derivatives bearing alkenyl side chains. The resulting alkenes or dienes were subjected to metathesis dimerization or ring-closing metathesis (RCM) reactions, respectively, by using a ruthenium indenylidene complex as the catalyst. The biological activity of the products thus obtained was tested in two different assays monitoring i) the proliferation of murine spleen cells induced by lipopolysaccharides (LPS) and concanavalin A (Con A), and ii) the vacuolar acidification of baby hamster kidney (BHK) cells. Compounds 4 and 21 suppressed Con A-induced T-cell proliferation much more potently than LPS-induced B-cell proliferation. Furthermore, compounds 4 and 26 markedly inhibited vacuolar acidification, although other compounds exhibited no or only marginal effects. Thus, the immunosuppressive activity of prodigiosins toward T-cell proliferation seems to be mediated through cellular targets distinct from vacuolar acidification, and the prodigiosin analogues might be powerful tools to dissect these biological responses. The X-ray crystal structure of the macrocyclic product 25 has been determined, showing that the replacement of one pyrrole ring of the parent compound 4 by a phenyl group does not alter the overall electronic features of the remaining heterocyclic ring system of these alkaloids.

Animals↗
PubMed2001

Alterations of the double-strand break repair gene MRE11 in cancer.

MRE11 plays a role in DNA double-strand break repair. Hypomorphic mutations of MRE11 have been demonstrated in ataxia-telangiectasia (AT)-like disorder. ATM mutations play a causal role in AT and have been demonstrated in lymphoid malignancies in patients without AT histories. By analogy with the relationship of ATM to lymphoid malignancies, it is probable that alterations of MRE11 are associated with tumor formation. We performed a mutation analysis of MRE11 in 159 unselected primary tumors. Three missense mutations at conserved positions were found in breast and lymphoid tumors. Additionally, an aberrant transcript without genomic mutation was found in a breast tumor. These findings suggest an occasional role for MRE11 alterations in the development of primary tumors.

Alternative Splicing↗
PubMed2001

Safety and efficacy of granulocyte and monocyte adsorption apheresis in patients with active ulcerative colitis: a multicenter study.

Active ulcerative colitis (UC) is characterized by activation and infiltration of granulocytes and monocytes/macrophages into the colonic mucosa. The infiltrated leukocytes can cause mucosal damage by releasing degradative proteases, reactive oxygen derivatives, and proinflammatory cytokines. The aim of this trial (conducted in 14 specialist centers) was to assess safety and efficacy of granulocyte and monocyte adsorption apheresis in patients with active UC most of whom were refractory to conventional drug therapy. We used a new adsorptive type extracorporeal column (G-1 Adacolumn) filled with cellulose acetate beads (carriers) of 2 mm in diameter, which selectively adsorb granulocytes and monocytes/macrophages. Patients (n = 53) received five apheresis sessions, each of 60 minutes duration, flow rate 30 ml per minute for 5 consecutive weeks in combination with 24.4 +/- 3.60 mg prednisolone (mean +/- SE per patient per day, baseline dose). During 60 minutes apheresis, 26% of granulocytes, 19.5% of monocytes and 2% of lymphocytes adsorbed to the carriers. At week 7, 58.5% of patients had remission or improved, the dose of prednisolone was reduced to 14.2 +/- 2.25 mg (n = 37). The apheresis treatment was fairly safe, only eight non-severe side effects (in 5 patients) were reported. Based on our results, we believe that in patients with active severe UC, patients who are refractory to conventional drugs, granulocyte and monocyte adsorption apheresis is a useful adjunct to conventional therapy. This procedure should have the potential to allow tapering the dose of corticosteroids, shorten the time to remission and delay relapse.

Adult↗
PubMed2001

Comparative analyses of the distribution of various transposable elements in Pyricularia and their activity during and after the sexual cycle.

We examined the distribution and activity of six transposable elements found in the blast fungus, Pyricularia spp. Sixty-eight isolates from various gramineous plants were used for the survey, and the elements were plotted on a dendrogram constructed on the basis of their rDNA-ITS2 sequences. MGR586 and Pot2 (Class II elements), Mg-SINE (SINE-like element) and MGR583 (LINE-like retrotransposon) were widely distributed among the Pyricularia isolates, suggesting that they are old elements which arose in, or invaded, the Pyricularia population at very early stages in its evolution. By contrast, the distribution of the LTR-retrotransposons MAGGY and Grasshopper was limited or sporadic, suggesting that they are relatively new elements which recently invaded the Pyricularia population by means of horizontal transfer events. The activity of these elements was evaluated by Southern analysis in progenies derived from a cross between a Setaria isolate and a Triticum isolate. Many new MAGGY signals were observed, which were absent in the parental isolates, at various stages of the sexual cycle and following vegetative growth. In contrast, the other elements yielded few, if any, such signals. Analysis of the sequences flanking the new MAGGY insertions revealed that they were each associated with a 5-bp target-site duplication at both ends of the insertion. These data suggested that MAGGY was the most active of the elements tested for transposition in Pyricularia.

Blotting, Southern↗
PubMed2001

Critical role of Caenorhabditis elegans homologs of Cds1 (Chk2)-related kinases in meiotic recombination.

Although chromosomal segregation at meiosis I is the critical process for genetic reassortment and inheritance, little is known about molecules involved in this process in metazoa. Here we show by utilizing double-stranded RNA (dsRNA)-mediated genetic interference that novel protein kinases (Ce-CDS-1 and Ce-CDS-2) related to Cds1 (Chk2) play an essential role in meiotic recombination in Caenorhabditis elegans. Injection of dsRNA into adult animals resulted in the inhibition of meiotic crossing over and induced the loss of chiasmata at diakinesis in oocytes of F(1) animals. However, electron microscopic analysis revealed that synaptonemal complex formation in pachytene nuclei of the same progeny of injected animals appeared to be normal. Thus, Ce-CDS-1 and Ce-CDS-2 are the first example of Cds1-related kinases that are required for meiotic recombination in multicellular organisms.

Amino Acid Sequence↗
PubMed2001

Evidence of Qi-gong energy and its biological effect on the enhancement of the phagocytic activity of human polymorphonuclear leukocytes.

In order to test for an effect of phosphate buffered saline (PBS) treated externally with Qi energy ("Qi-treated" PBS) on the phagocytic activity of human polymorphonuclear leukocytes (PMNs), rigorously controlled experiments employing masking and randomized procedures were carried out under independent monitoring. In all experiments, Qi treatment was externally applied under monitoring to newly purchased unopened 100 ml bottles of PBS, and the PMN phagocytic activity was assayed by one experimenter in masked, randomized and monitored conditions using a highly sensitive chemiluminescence method. Phagocytic activity data were obtained in triplicate for each sample and then statistically analyzed. The PBS samples Qi-treated by the Qi-gong master and by one of the Qi-gong trainees showed clear stimulation of PMN phagocytic activity which was significant statistically, and this phenomenon was highly reproducible. Out of 10 experiments by the Qi-gong master, only twice did Qi-treatment fail to influence the PBS. The activity of Qi-treated PBS decayed over days or weeks. Furthermore, it was found that Qi-treated PBS had decreased phagocytic stimulatory activity after microwave treatment, but not after autoclave treatment. We also demonstrated that microwave irradiation and infrared laser pulse irradiation have similar effects on PBS as Qi-treatment. The results obtained in this experiment provide evidence of the existence of Qi energy, its ability to influence an electrolyte solution and its biological effect. Furthermore, microwave or infrared laser pulse treatment was found to partly mimic the Qi-treatment of PBS.

Adolescent↗