Biomedical subjects

Kingo Fujimura

Publications and source records attributed to Kingo Fujimura.

15 recordsLinked to original sources

PubMed2005

Patient characteristics in ticlopidine hydrochloride-induced liver injury: Case-control study.

BACKGROUND: Ticlopidine hydrochloride-induced liver abnormalities have been reported in the world. In Japan, the five-year (1995-2000) spontaneous serious reports of ticlopidine finds that liver injury accounts for about half of the reports. OBJECTIVE: Clinical characteristics of ticlopidine-induced liver injury were investigated to establish the prevention strategy. METHODS: We used a medical information system at Hiroshima University Hospital and analyzed statistically. RESULTS: In this study 288 cases were reviewed. Sixty-two cases were identified as the Cases that showed liver function abnormality after ticlopidine administration. And 226 cases were identified as the Controls. There were no significant differences in gender, age or daily dose between the two groups. Fluctuation of liver function was observed within 30 days in the most of Cases and cholestatic type accounted for about 60%. The risk of this abnormality increased significantly in patients with pre-existing abnormal liver or renal function [odds ratio (95% CI): 2.96 (1.43-6.13), p=0.005; 2.47 (1.13-5.39), p=0.037]. The renal protective agent, an oral carbonaceous adsorbent, reduced the risk of ticlopidine-induced liver function abnormalities in patients with renal abnormalities significantly [odds ratio (95% CI): 0.04 (0.002-0.767), p=0.004]. CONCLUSIONS: Liver function tests should be checked frequently, especially in cases with pre-existing liver or renal function abnormalities.

Journal Article↗

PubMed2005

Glanzmann thrombasthenia with acute myeloid leukemia successfully treated by bone marrow transplantation.

We report successful treatment by bone marrow transplantation (BMT) in an acute myeloid leukemia (AML) patient with Glanzmann thrombasthenia (GT). Genetic analysis revealed that a novel point mutation in exon 3 of the GPIIb gene led to abnormal splicing resulting in an amino acid substitution and an in-frame deletion of 3 amino acid residues. Expression studies suggested a rapid degradation of the uncomplexed protein within the cells. Induction therapy for AML was performed with frequent platelet transfusions because of the patient's severe hemorrhagic manifestations. In the second remission, the patient was successfully treated by BMT from an HLA-matched unrelated donor. Platelet function returned to normal, and the GT phenotype completely disappeared. Our experience suggests that BMT is a curative therapeutic strategy for GT. Furthermore, we believe this study is the first to demonstrate that engraftment after BMT for AML can be determined by monitoring the congenital genetic defect of GT.

Acute Disease↗

PubMed2005

Is eradication therapy useful as the first line of treatment in Helicobacter pylori-positive idiopathic thrombocytopenic purpura? Analysis of 207 eradicated chronic ITP cases in Japan.

A retrospective study was performed to determine the prevalence of Helicobacter pylori (H pylori) infection, the effect of H pylori eradication on platelet counts, and the characteristic clinical features of chronic immune or idiopathic thrombocytopenic purpura (ITP) with H pylori infection. H pylori infection was found in 300 patients, a group that was significantly older (P < .005) and had more cases of hyperplastic megakaryocytes in the bone marrow (P = .01) than patients without H pylori infection. H pylori eradication therapy was performed in 207 H pylori-positive ITP cases, and the platelet count response was observed in 63% of the successful eradication group and in 33% of the unsuccessful eradication group (P < .005). In the successful group, the complete remission and partial remission rates were 23% and 42%, respectively, 12 months after eradication. In the majority of responders, the platelet count response occurred 1 month after eradication therapy, and the increased platelet count continued without ITP treatment for more than 12 months. H pylori eradication therapy was effective even in refractory cases, which were unresponsive to splenectomy. In conclusion, H pylori infection was involved in most ITP patients older than 40 years in Japan, and eradication therapy should be the first line of treatment in H pylori-positive ITP patients.

Adult↗

PubMed2005

Helicobacter pylori infection and idiopathic thrombocytopenic purpura.

A treatment strategy for idiopathic thrombocytopenic purpura (ITP) is considered with the aim of cure or management of the bleeding tendency. In 1998, Gasbarrini et al reported a high prevalence of Helicobacter pylori infection in patients with ITP and showed that platelet recovery occurred after eradication therapy in most cases. Since then, many studies were performed to evaluate eradication therapy. This article discusses the incidence of H pylori infection in ITP, characteristic clinical features in H pylori-positive ITP, the effectiveness of eradication on platelet count increase, and the mechanisms of development of ITP by H pylori infection. Overall, there was a positive association between H pylori infection and ITP, and eradication of bacterium was accompanied by a significant increase in platelet counts in more than 50% of H pylori-positive ITP cases. These findings suggest that H pylori infection is involved in the mechanisms of thrombocytopenia in most cases of ITP in middle-aged and older patients. This approach could be beneficial to some ITP patients, but there were some uncertainties raised. To confirm the effectiveness of eradication therapy in H pylori-positive ITP, prospective studies conducted in several countries with a new treatment protocol are required, with a large number of ITP cases and longer follow-up.

Blood Platelets↗

PubMed2004

Glanzmann thrombasthenia associated with a 21-amino acid deletion (Leu817-Gln837) in glycoprotein IIb due to abnormal splicing in exon 25.

We report a novel genetic defect in a Japanese patient with type I Glanzmann thrombasthenia. The glycoprotein (GP) Ilb complementary DNA (cDNA) from platelet messenger RNA had a 63-base pair deletion in the 5' boundary of exon 25, resulting in an in-frame deletion of 21 amino acid residues (Leu817-Gln837) in the calf-2 domain. The deleted region was present in the genomic DNA, but the splice acceptor site (AG) of exon 25 was mutated to AC, leading to the use of an AG sequence in the middle of exon 25 as an abnormal cryptic splice acceptor site. The effect of this deletion on protein synthesis was further analyzed. Mutant GPIIb-IIIa complexes were not detected on the surfaces of cells cotransfected with cDNAs of mutant GPIIb and normal GPIIIa. Mutant pro-GPIIb was detected in cell lysates and was coimmunoprecipitated with an anti-GPIIb-IIIa complex antibody. Immunostaining demonstrated that the mutant pro-GPIIb colocalized with an endoplasmic reticulum protein, calnexin, within the cells. These results indicate that complex formation was not completely prevented and that impairment of the subsequent transport was the major reason for the defect in cell surface expression. The data suggest that the GPIIb calf-2 domain is important for intracellular transport of GPIIIb-IIIa complexes.

Antigens, Surface↗

PubMed2004

Progressive myeloma after thalidomide therapy in a patient with immature phenotype of myeloma (plasma) cells.

In our experience with thalidomide treatment for refractory multiple myeloma (MM), most patients with progressive disease (PD) did not show an increase in M-protein despite the tumor burden of myeloma cells. This finding led us to suspect that proliferation of immature myeloma cells showing MPC-1(-)/CD49e(-) phenotype may be a sign of PD. We report the results of consecutive analysis of the phenotype of myeloma (plasma) cells in an MM patient with PD during treatment with thalidomide. The myeloma cells decreased by thalidomide therapy were mature (MPC-1(+)/CD49e(+)) and intermediate (MPC-1(+)/CD49e(-)) types. When the patient was in the PD state, extramedullary plasmacytoma was recognized without proliferation of myeloma cells in the bone marrow (BM). The phenotype of myeloma (plasma) cells in both of these locations was that of immature myeloma cells (MPC-1(-)/CD49e(-)), and they showed decreased intensity of CD38 expression. The level of immunoglobulin G (IgG) in serum was decreased, and myeloma (plasma) cells in BM did not increase in PD. Although these clinical features may not be specific to MM patients in PD undergoing treatment with thalidomide, we suggest that immature myeloma cells may be resistant to thalidomide.

Aged↗

PubMed2003

Effect of a single injection of humanized anti-CD154 monoclonal antibody on the platelet-specific autoimmune response in patients with immune thrombocytopenic purpura.

Blockade of the CD40/CD154 signal is a potential immunomodulatory strategy for T-cell-mediated diseases. As a part of a phase 1, multicenter, dose-escalating trial of humanized monoclonal antibody to CD154 (IDEC-131/E6040) in patients with refractory immune thrombocytopenic purpura (ITP), the autoimmune response to glycoprotein IIb/IIIa (GPIIb/IIIa) was evaluated at successive time points. Five patients each were given a single infusion of 1, 2, 5, or 10 mg/kg IDEC-131/E6040 and followed for 3 months. All adverse events were mild, and there were no severe infections or thromboembolic events. No increase in platelet count was observed in patients treated at 1, 2, or 5 mg/kg, but an increase was observed in 3 patients treated at 10 mg/kg. In only the patients treated at 5 or 10 mg/kg, the frequency of B cells producing anti-GPIIb/IIIa antibodies, GPIIb/IIIa-induced T-cell proliferation, and anti-GPIIb/IIIa antibody production by antigen-dependent T-B-cell collaboration were all suppressed in parallel after the treatment, with a slow return to baseline. In contrast, T-cell response to an irrelevant antigen was not affected. These findings suggest that CD40/CD154 blockade therapy is potentially effective for refractory ITP, through selective suppression of autoreactive T and B cells to platelet antigens.

Adult↗

PubMed2003

Production of functional platelets by differentiated embryonic stem (ES) cells in vitro.

Megakaryocytes and functional platelets were generated in vitro from murine embryonic stem (ES) cells with the use of a coculture system with stromal cells. Two morphologically distinctive megakaryocytes were observed sequentially. Small megakaryocytes rapidly produced proplatelets on day 8 of the differentiation, and large hyperploid megakaryocytes developed after day 12, suggesting primitive and definitive megakaryopoiesis. Two waves of platelet production were consistently observed in the culture medium. A larger number of platelets was produced in the second wave; 104 ES cells produced up to 108 platelets. By transmission electron microscopy, platelets from the first wave were relatively rounder with a limited number of granules, but platelets from the second wave were discoid shaped with well-developed granules that were indistinguishable from peripheral blood platelets. ES-derived platelets were functional since they bound fibrinogen, formed aggregates, expressed P-selectin upon stimulation, and fully spread on immobilized fibrinogen. These results show the potential utility of ES-derived platelets for clinical applications. Furthermore, production of gene-transferred platelets was achieved by differentiating ES cells that were transfected with genes of interest. Overexpression of the cytoplasmic domain of integrin beta3 in the ES-derived platelets prevented the activation of alphaIIbbeta3, demonstrating that this system will facilitate functional platelet studies.

Animals↗

PubMed2003

Thrombospondin-bound integrin-associated protein (CD47) physically and functionally modifies integrin alphaIIbbeta3 by its extracellular domain.

Integrin-associated protein (IAP/CD47) is a receptor for the C-terminal cell binding domain of thrombospondin (TS). A peptide from the C-terminal cell binding domain, KRFYVVMWKK (4N1K) binds to IAP and stimulates the integrin-dependent cell functions, including platelet aggregation. We investigated the mechanism by which TS-bound IAP modulates the affinity of platelet integrin, alphaIIbbeta3. Platelet aggregation induced by 4N1K was not completely inhibited by energy depletion with sodium azide and 2-deoxy-d-glucose, although ADP or collagen-induced platelet response was completely inhibited. The binding of ligand-mimetic antibody PAC1 to alphaIIbbeta3 was also induced in the energy-depleted platelets. In the transfected Namalwa cells, 4N1K induced activation of the alphaIIbbeta3 with mutated beta3 (Ser-752 to Pro), which is a non-responsive form to inside-out signaling, as well as wild type alphaIIbbeta3. The truncated form of IAP with only the extracellular immunoglobulin-like (Ig) domain was sufficient for the activation of alphaIIbbeta3 in Chinese hamster ovary cells, although the IAP-mediated intracellular signaling was abolished, which was monitored by the absence of down-regulation of mitogen-activated protein kinase phosphorylation. Furthermore, the soluble recombinant Ig domain of IAP induced PAC1 binding to alphaIIbbeta3 on Chinese hamster ovary cells when added with 4N1K. Physical association between the soluble recombinant Ig domain of IAP and purified alphaIIbbeta3 was detected in the presence of 4N1K. These data indicate that the extracellular Ig domain of IAP, when bound to TS, interacts with alphaIIbbeta3 and can change alphaIIbbeta3 in a high affinity state without the requirement of intracellular signaling. This extracellular event would be a novel mechanism of affinity modulation of integrin.

Amino Acid Sequence↗

PubMed2003

[Glucocorticoids therapy as a first line treatment in ITP].

Idiopathic thrombocytopenic purpura(ITP) is an immunohematological disorder for which appropriate diagnostic and treatment strategies are unclear. In 1982 in Japan and 1996 in ASH, guideline for ITP treatment was produced, respectively. These guidelines selected the steroid for the first line treatment. Appropriate steroid treatment was recommended based on the severity or grade of bleeding and platelet counts. Patients with platelet counts above 50,000 do not require treatment ordinarily. Treatment was indicated in-patients with platelet counts under 20,000-30,000, and those with platelet counts under 50,000 with presence of bleeding tendency or risk factor for bleeding. Most ITP patients responded well with initial steroid treatment and 33% of them had a complete remission from ITP, but remaining patients decreased platelet counts with the steroid dose reduction. The management of the bleeding symptoms without the adverse effects is an important point of steroid medication in ITP after first line treatment.

Glucocorticoids↗

PubMed2003

[Single-agent thalidomide for advanced and refractory multiple myeloma].

Thalidomide as a single agent (200-400 mg/day) was administered in fourteen cases of refractory myeloma, from March 2001 till February 2002. The median age was 71 years (range 58 to 85 years), and the efficacy of thalidomide was observed in cases receiving treatment for at least three consecutive months. Response was evaluated in February 2002, according to the criteria for assessment of response described by Kakimoto et al. At the time of evaluation, two cases were in the PR2 state, one in PR3, two were stable, and three were PD. Evaluation of the response was not possible in six cases in whom treatment had to be discontinued due to intolerable side effects. The response to thalidomide was variable, with some cases responding well even to a low dose (200 mg/day) while a few others showed an early relapse due to the refractory nature of the disease in its response to the drug. The efficacy of treatment seemed to be correlated with the maturation pattern of myeloma cells. Side effects included neurological complications like somnolence, physiological symptoms such as constipation and so on, etc but all were relieved with symptomatic treatment. The drug was well tolerated in geriatric patients. Neutropenia was a dose limiting factor with half of the cases (7/14) presenting with severe neutropenia (grade 3-4), but a response was observed in all of them on administration of G-CSF. Thromboembolism occurred in two cases, the cause of which is not clear. These results suggest that thalidomide is a well tolerated drug and can be considered as a mainstay in the therapy of refractory myeloma.

Aged↗

PubMed2002

A new member of the LIM protein family binds to filamin B and localizes at stress fibers.

Human filamins are 280-kDa proteins containing an N-terminal actin-binding domain followed by 24 characteristic repeats. They also interact with a number of other cellular proteins. All of those identified to date, with the exception of actin, bind to the C-terminal third of a filamin. In a yeast two-hybrid search of a human placental library, using as bait repeats 10-18 of filamin B, we isolated a cDNA coding for a novel 374 amino acid protein containing a proline-rich domain near its N terminus and two LIM domains at its C terminus. We term this protein filamin-binding LIM protein-1, FBLP-1. Yeast two-hybrid studies with deletion mutants localized the areas of interaction in FBLP-1 to its N-terminal domain and in filamin B to repeats 10-13. FBLP-1 mRNA was detected in a variety of tissues and cells including platelets and endothelial cells. We also have identified two FBLP-1 variants. Both contain three C-terminal LIM domains, but one lacks the N-terminal proline-rich domain. Transfection of FBLP-1 into 293A cells promoted stress fiber formation, and both FBLP-1 and filamin B localized to stress fibers in the transfected cells. The association between filamin B and FBLP-1 may play a hitherto unknown role in cytoskeletal function, cell adhesion, and cell motility.

Actins↗

PubMed2002

Effects of pegylated recombinant human megakaryocyte growth and development factor in patients with idiopathic thrombocytopenic purpura.

We conducted a phase 1-2 clinical trial to evaluate the effect of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) in patients with chronic idiopathic thrombocytopenic purpura (ITP) refractory to standard therapy who had platelet counts below 30 x 10(9)/L. Four patients received PEG-rHuMGDF (0.5 microg/kg of body weight per day) by daily intravenous injection for up to 7 days. Administration of PEG-rHuMGDF increased platelet counts in 3 patients. A striking thrombocytosis occurred in 2 patients, whose platelet counts were elevated to more than 700 x 10(9)/L a week after the last administration of PEG-rHuMGDF and returned to baseline levels within 4 to 6 weeks. Before the platelet peak, the percentage of reticulated platelets increased transiently in 3 patients tested, including one patient who had no response. Bleeding episodes decreased after the start of PEG-rHuMGDF therapy. These results suggest that PEG-rHuMGDF might have a clinical benefit in ameliorating thrombocytopenia associated with ITP.

Adult↗

PubMed2002

Novel alternatively spliced form of beta(3)-endonexin.

beta(3)-Endonexin is a binding protein to the cytoplasmic tail of beta(3) integrin and can activate alpha(IIb)beta(3) in Chinese hamster ovary (CHO) cells. Initially, two forms were identified, and only the shorter form showed the function. However, it localized mainly to the nucleus because of a nuclear localization signal (K(62)RKK). We identified two additional forms of beta(3)-endonexin. One encoded 177 amino acids and was identical to the protein previously reported as a thyroid hormone receptor-binding protein. The other is a novel shortest form encoding 62 amino acids. Although the novel form lacked nuclear localization signal and was observed diffusely in the cytoplasm of transfected cells, this form did not show interaction with beta(3) integrin. Then, the ideal form as an integrin modulator was not found among these isoforms. Nevertheless, when the nuclear localization signal of the shorter form was disrupted, beta(3)-endonexin was localized near the cell surface and modulated the affinity of alpha(IIb)beta(3) more intensively. These results suggest the presence of various isoforms and the relationship between subcellular localization and integrin-activating function of beta(3)-endonexin.

Alternative Splicing↗

PubMed2002

Nationwide study of idiopathic thrombocytopenic purpura in pregnant women and the clinical influence on neonates.

Idiopathic thrombocytopenic purpura (ITP) occurs more commonly in young women during the reproductive years. To obtain information for management of ITP in pregnancy, we performed a nationwide retrospective survey. Findings from a total of 284 pregnant women with ITP and their 286 newborn infants were available for analysis. The bleeding tendency at delivery was managed chiefly with corticosteroid, intravenous high-dose gamma-globulin, and platelet transfusion. Maternal complications occurred in 77 cases (27.1%) and were frequently seen in cases with poor control of ITP. Neonatal abnormalities, which were not influenced by the clinical state of the mother, occurred at a frequency of 17.8%. Thrombocytopenia in neonates occurred in 48 cases (22.4%), and bleeding tendency was found in 16 cases (6.3%) without severe bleeding. Prediction of thrombocytopenia in neonates was difficult. However, infants from splenectomized mothers with well-controlled ITP showed thrombocytopenia more frequently than those from nonsplenectomized mothers. Mothers treated with steroids at doses greater than 15 mg/day showed a high frequency of maternal complications and fetal abnormal body weight. These observations will be useful in the management of pregnant women with ITP and their infants.

Abnormalities, Drug-Induced↗