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Biomedical subjects

M Yasui

Publications and source records attributed to M Yasui.

At least 19 recordsLinked to original sources
PubMed2006

Increased intensity of acute graft-versus-host disease after reduced-intensity bone marrow transplantation compared to conventional transplantation from an HLA-matched sibling in children.

Eight children underwent reduced-intensity stem cell transplantation (RIST) from an HLA-matched sibling. They received a fludarabine-melphalan based preparative regimen. Stem cell source was bone marrow, and GVHD prophylaxis consisted of cyclosporine A alone. Acute GVHD grade II-IV and grade III-IV were observed in four (50%) and three (37.5%), respectively, out of these eight patients. This incidence was significantly higher than that after conventional bone marrow transplantation, without severe tissue damage, in the same setting of stem cell source and GVHD prophylaxis. Although the number of patients is small, our results suggest that incidence of acute GVHD after RIST for children is significant. It should be remembered that RIST for children does not seem to be an easy transplant procedure from the viewpoint of acute GVHD, although RIST is less toxic.

Adolescent↗
PubMed2006

Role of intercellular adhesion molecule-1 in a murine model of toluene diisocyanate-induced asthma.

BACKGROUND: Adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) are thought to contribute to the airway inflammation and airway hyper-responsiveness (AHR) of allergic asthma. Some differences from allergic asthma have been noted, including airway neutrophilia, and the involvement of ICAM-1 in toluene diisocyanate (TDI) asthma is currently unclear. OBJECTIVE: We utilized mice lacking ICAM-1 expression (ICAM-1(-/-)) to investigate the role of ICAM-1 in airway inflammation and AHR in TDI-induced asthma. METHODS: Male C57BL/6J mice (ICAM-1(+/+)) and ICAM-1(-/-) mice were intranasally sensitized to TDI solution or solvent alone. Airway inflammation, AHR and cytokine secretion were assessed 24 h after challenge by TDI or solvent. The production of antigen-specific IgG and IgE by TDI sensitized and non-sensitized mice was determined. RESULTS: TDI challenge to ICAM-1(+/+) mice induced an increase in airway inflammatory cell numbers, AHR and cytokine secretion of TNF-alpha, macrophage inflammatory protein-2 (MIP-2), IL-4, IL-5 and IFN-gamma into the bronchoalveolar lavage fluid. All these pathophysiological changes were reduced in ICAM-1(-/-) mice. Serum levels of TDI-specific IgG and IgE of ICAM-1(-/-) and ICAM-1(+/+) mice were comparable. CONCLUSION: These results suggest that ICAM-1 plays an essential role in airway inflammation and AHR in TDI-induced asthma.

Animals↗
PubMed2005

Cyber visual training as a new method for the mastery of endoscopic surgery.

BACKGROUND: We devised a new method incorporating cyber visual training whereby novices in endoscopic surgery are instructed via repetition of a video-recorded procedure. We then conducted a study designed to investigate the impact of this cyber visual training on the mastery of intracorporeal knot-tying as an endoscopic technique. METHODS: For the cyber visual training a 10-min video of the same procedure was replayed at normal, slow, and rapid speeds or presented in a series of still images. The training was undertaken by 36 medical students and 1st year trainee doctors who had had no experience of endoscopic surgery. They were divided into three groups, each of all received the same introductory lecture. Group A was only given training with the instructor for 15 min. Group B trained with the instructor for 15 min and was allowed self-training for 10 min. Group C viewed the cyber video beforehand and then underwent training with the instructor for 15 min. For all participants, the time required to complete a knot-tying task was measured and the level of endoscopic skill before and after the training was assessed using a virtual reality system the minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR), in terms of the following three parameters: time, errors, and efficiency of hand movements. The Steel-Dwass test was used to evaluate the differences among the three groups in task performance. RESULTS: Group C completed the knot-tying task faster than group A (p = 0.0375), but there were significant differences between groups A and B and groups B and C. There were no significant differences in the parameters assessed using the MIST-VR. CONCLUSIONS: Our new concept of cyber visual training is effective for mastering the knot-tying technique. This type of training should be widely applicable to other procedures, such as dissection, clipping, and hemostasis.

Adult↗
PubMed2005

Unrelated donor bone marrow transplantation for 100 pediatric patients: a single institute's experience.

In all, 100 unrelated donor bone marrow transplantations (UD-BMT) were performed in our institute between October 1993 and January 2003. Of 93 evaluable patients, 73 patients had hematological malignancy, 13 had nonmalignancy and seven had lymphoproliferative disease. The estimated 9-year event-free survival (EFS) rate was 57.1+/-5.5% in all patients. In the following analyses of the patients with hematological malignancy, the standard group had significantly better EFS than the high-risk group (61.5+/-7.0 vs 35.6+/-9.7%, P=0.02), and the EFS rate of the tacrolimus (FK-506)+methotrexate (MTX)+/-methylprednisolone prophylactic group for graft-versus-host disease was superior to that of the FK-506 without MTX group (75.7+/-8.0 vs 55.8+/-7.6%, P=0.02). When we compared the EFS rates of the FK506+MTX+/-methylprednisolone (mPSL) group and the HLA-matched related donor BMT group in our institute, these were almost similar (75.7+/-8.1 vs 68.4+/-9.3%). Therefore, UD-BMT using FK-506+MTX+/-mPSL is a safe and useful method for children with hematological malignancy who require allogeneic BMT.

Adolescent↗
PubMed2005

Clinical usefulness of oral granisetron hydrochloride for alleviation of delayed nausea and vomiting induced by CPT-11.

This open label pilot study evaluated the safety and efficacy of the oral 5-HT3 receptor antagonist granisetron for prophylaxis of delayed chemotherapy-induced nausea and vomiting (CINV) in 30 patients with advanced or recurrent colorectal cancer. Patients were studied during two cycles of a 5-week regimen with irinotecan (CPT-11) and UFT. Patients received prophylactic anti-emetic therapy that included intravenous granisetron. If Grade 1 or higher severity gastrointestinal symptoms occurred during 6 days after CPT-11 administration in Cycle 1, then oral granisetron was administered daily for the following 5 days of CPT-11 in Cycle 2. Sixteen patients (53.3%) experienced delayed CINV in Cycle 1. The incidence of Grade 2 or higher vomiting was 32.1% and 27.7% in Cycles 1 and 2 in males (P = 0.554) respectively, and 54.6% and 32.4% in females (P = 0.001) respectively. Granisetron is effective against delayed Grade 2 or higher vomiting induced by CPT-11/UFT in female patients, although granisetron alone may not sufficiently control nausea induced by this regimen.

Administration, Oral↗
PubMed2005

Up regulated expression of fractalkine/CX3CL1 and CX3CR1 in patients with systemic sclerosis.

BACKGROUND: Fractalkine expressed on endothelial cells mediates activation and adhesion of leucocytes expressing its receptor, CX(3)CR1. Soluble fractalkine exhibits chemotactic activity for leucocytes expressing CX(3)CR1. OBJECTIVE: To determine the role of fractalkine and its receptor in systemic sclerosis (SSc) by assessing their expression levels in patients with this disease. METHODS: The expression of fractalkine and CX(3)CR1 in the skin and lung tissues was immunohistochemically examined. Circulating soluble fractalkine levels were examined by enzyme linked immunosorbent assay (ELISA). Blood samples from patients with SSc were stained for CX(3)CR1 with flow cytometric analysis. RESULTS: CX(3)CR1 levels on peripheral monocytes/macrophages and T cells were found to be raised in patients with diffuse cutaneous SSc. The numbers of cells expressing CX(3)CR1, including monocytes/macrophages, were increased in the lesional skin and lung tissues from patients with diffuse cutaneous SSc. Fractalkine was strongly expressed on endothelial cells in the affected skin and lung tissues. Soluble fractalkine levels were significantly raised in sera and were associated with raised erythrocyte sedimentation rates, digital ischaemia, and severity of pulmonary fibrosis. CONCLUSIONS: Up regulated expression of fractalkine and CX(3)CR1 cooperatively augments the recruitment of mononuclear cells expressing CX(3)CR1 into the affected tissue of SSc, leading to inflammation and vascular injury.

Adult↗
PubMed2005

Cytotoxic chemotherapy successfully induces durable complete remission in 2 patients with mosquito allergy resulting from Epstein-Barr virus-associated T-/natural killer cell lymphoproliferative disease.

Recent findings indicate that Epstein-Barr virus (EBV)-infected T-/natural killer (NK) cells play an important role in the pathogenesis of mosquito allergy, and most patients with mosquito allergy die early in life if not properly treated. Over the last 7 years, we have been using combination chemotherapy and allogeneic stem cell transplantation for the treatment of EBV-associated T-/NK cell lymphoproliferative disease (LPD) in which chronic active EBV infection and mosquito allergy were included. As of this writing, we have successfully treated 2 patients with mosquito allergy with chemotherapy in which EBV-infected T-/NK cells were eradicated. The findings suggest the possible role of chemotherapy in the treatment of EBV-associated T-/NK cell LPD.

Animals↗
PubMed2003

Unrelated bone marrow transplantation for Epstein-Barr virus-associated T/NK-cell lymphoproliferative disease.

Epstein-Barr virus (EBV)-associated T/NK-cell lymphoproliferative disease (LPD) has been linked to several different disorders, including chronic active EBV infection, EBV-associated hemophagocytic syndrome, hypersensitivity to mosquito bites, hydroa vacciniforme, aggressive NK-cell leukemia, and nasal/nasal-type NK-cell lymphoma. In most instances, these disorders are refractory to conventional treatments and have a poor prognosis. Here, we report a new treatment strategy for EBV-associated T/NK-cell LPD, consisting of immunochemotherapy, intensive combination chemotherapy, and stem cell transplantation. The five patients studied, two with T-cell and three with NK-cell LPD, lacked a human leukocyte antigen-matched, related donor, and therefore received bone marrow grafts from HLA-matched, unrelated donors. The preconditioning regimen consisted of total-body irradiation (12 Gy), etoposide (900 mg/m(2)), and cyclophosphamide (120 mg/kg) or melphalan (210 mg/m(2)). All patients had residual LPD by a quantitative PCR technique prior to transplantation. After unrelated bone marrow transplantation (UBMT), four of the five patients remain in continuous complete remission at a median of 19 months, without detectable EBV-DNA in peripheral blood. Thus, UBMT appears to be a reasonable option for the treatment of patients with EBV-associated T/NK-cell LPD. Detection of EBV-DNA by PCR offers an important tool for assessing minimal residual disease in patients with EBV-associated T/NK-cell LPD.

Adolescent↗
PubMed2003

Graft-versus-tumor effect in a patient with advanced neuroblastoma who received HLA haplo-identical bone marrow transplantation.

A 5-year-old boy received CD34-positive HLA haplo-identical bone marrow transplantation from his father as treatment for refractory advanced neuroblastoma. He had residual disease in the para-aortic lymph nodes and multiple bones after the transplant. However, all of his residual disease had disappeared completely 3 years later. He developed grade I acute graft-versus-host disease (GVHD) but had no symptoms of chronic GVHD or any other complications. This case demonstrates the possibility of a graft-versus-tumor effect against neuroblastoma by HLA-mismatched allogeneic hematopoietic stem cell transplantation.

Bone Marrow Transplantation↗
PubMed2003

Characteristics of pulmonary Mycobacterium avium-intracellulare complex (MAC) infection in comparison with those of tuberculosis.

To clarify the clinical features of pulmonary Mycobacterium avium-intracellulare complex (MAC) infection, we retrospectively evaluated clinical manifestations, laboratory data, chest and maxillary sinus computed tomographic scans and induced sputum findings in 26 with MAC infection in comparison with 104 patients with tuberculosis (TB) infection. We found that carbohydrate antigen 19-9 (CA 19-9) and immunoglobulin A (IgA) in the serum and percentage of neutrophils in the sputum were significantly higher, and sinusitis was significantly more frequent in patients with MAC compared with patients with TB. MAC infection might be more strongly associated with impaired upper and lower airway defense mechanism in comparison with TB.

Aged↗
PubMed2002

An arming yeast with the ability to entrap fluorescent 17beta-estradiol on the cell surface.

We constructed a novel surface-engineered yeast displaying the ligand-binding domain of the rat estrogen receptor (ERLBD). ERLBD, display of which on the yeast cell surface was confirmed by immunofluorescence, possessed strong binding activity to fluorescent 17beta-estradiol - an analogue of the natural ligand of the estrogen receptor - that was comparable to the activity of the native receptor. Environmental homeostasis has recently been disturbed by endocrine disruptors, which cause confusion in the hormone secretion system. It is therefore very important to identify chemical compounds with hormone-like activity and remove them from the environment. The present results demonstrate that the new arming yeast displaying ERLBD on its cell surface will be capable of screening, entrapping, and removing estradiol-like compounds from the environment.

Animals↗
PubMed2001

Bis(hfac)-copper(II) complexes bridged by pyrimidines showing magnetic interactions.

Crystals of bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)bispyrimidinecopper(II) (1), bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)bis(4-methylpyrimidine)copper(II) (2), bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)bis(quinazoline)copper(II) (3) showed ferromagnetic interactions at extremely low temperature. Crystal structure analyses revealed that these complexes were catena-bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)[mu-pyrimidine-N(1):N(3)]copper(II), [Cu(hfac)(2)(pm)(2)](n), catena-bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)[mu-4-methylpyrimidine-N(1):N(3)]copper(II), [Cu(hfac)(2)(4-Me-pm)](n), and catena-bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)[mu-pyrimidine-N(1):N(3)]copper(II), [Cu(hfac)(2)(qz)](n), for (1), (2) and (3), respectively. In (1) and (2) the pyrimidines bridge the Cu atoms with an axial-equatorial mode to form one-dimensional spiral chains. Complex (3) also forms a one-dimensional chain structure. The coordination mode of (3) is axial-axial at room temperature, while axial-equatorial at 120 K. On the other hand, the structure of the other modification of the 4-methylpyrimidine complex (4), showing paramagnetic properties, was revealed to be a trinuclei complex bridged by two 4-methylpyrimidines, tris[bis-(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)copper(II)][bis-mu-4-methyl-pyrimidine-N(1):N(3)]. The chain structures with an axial-equatorial coordination mode of the bridging organic moieties should play an important role in the appearance of the ferromagnetic interactions.

Journal Article↗
PubMed2001

Solid state optical activity of dichalcogenides: isolation by chiral crystallization and determination of absolute configuration.

[reaction--see text] Optically active diphenyl dichalcogenides were isolated in bulk for the first time by chiral crystallization. The absolute configuration of the P-helical enantiomer of diphenyl disulfide was determined by X-ray crystallography. On the basis of this determination and considering the similarities of the Cotton effects of diphenyl diselenide and ditelluride, the absolute configuration of optically active diphenyl dichalcogenides could be assigned. Furthermore, stereochemistry of chiral crystallization could be controlled by using an optically active crystal as a seed crystal.

Chalcone↗
PubMed2001

Two-component molecular crystals from N-heteroaromatics and nitrobenzoic acids.

Five two-component molecular crystals, benzimidazolium 3-nitrobenzoate, C(7)H(7)N(2)(+).C(7)H(4)NO(4)(-), (I), benzimidazolium 4-nitrobenzoate, C(7)H(7)N(2)(+).C(7)H(4)NO(4)(-), (II), 1H-benzotriazole-3-nitrobenzoic acid (1/1), C(6)H(5)N(3).C(7)H(5)NO(4), (III), imidazolium 3-nitrobenzoate, C(3)H(5)N(2)(+).C(7)H(4)NO(4)(-), (IV), and imidazolium 4-nitrobenzoate, C(3)H(5)N(2)(+).C(7)H(4)NO(4)(-), (V), were prepared with the aim of making chiral crystals. Only (I) crystallizes in a chiral space group. The molecules of (I) and (II) are linked by hydrogen bonds to form 2(1) spiral chains. In (III), (IV) and (V), macrocyclic structures are formed from two acid and two base components, by an alternate arrangement of the acid and base moieties.

Journal Article↗
PubMed2001

Dipyrimidine-copper(II) dinitrate complexes showing magnetic interactions.

Crystals of Cu(II)(NO(3))(2)(pm)(3) (1), and two crystalline forms of Cu(II)(NO(3))(2)(H(2)O)(2)(pm)(2), (2) and (3), showed ferromagnetic, antiferromagnetic and paramagnetic interactions at extremely low temperatures, respectively. Crystal structure analyses revealed that the complexes were catena-dinitrato[mu-pyrimidine-kappaN(1):kappaN(3)]-(pyrimidine-N(1))copper(II), [Cu(NO(3))(2)(pm)(2)](n), catena-diaquadinitrato[mu-pyrimidine-kappaN(1):kappaN(3)]copper(II), [Cu(NO(3))(2)(H(2)O)(2)(pm)](n), and diaquadinitratodipyrimidinecopper(II), Cu(NO(3))(2)(H(2)O)(2)(pm)(2) for (1), (2) and (3), respectively. In (1) the Cu atom is coordinated by the two nitrates and N atoms of the non-bridging pyrimidine and bridging pyrimidine to form a one-dimensional coordination polymer. The complex is a five-coordinated square pyramid and can be regarded as a pseudo-seven-coordinated complex, since other short non-bonding Cu.O contacts are observed. In the crystals of (2) the pyrimidine bridges the Cu atoms to form a one-dimensional coordination chain. On the other hand, complex (3) is not a coordination polymer. It is important to form a coordination polymer for the appearance of the magnetic interactions. Types of coordination of the bridging organic moieties should also play an important role in magnetic properties. Magnetic measurements of (1) and (2) show that they are good examples of uniform S = 1/2 ferro- and antiferromagnetic Heisenberg chains with exchange parameters 2J/kB = +1.8 and -36 K, respectively.

Journal Article↗
PubMed2001

Translesional synthesis on a DNA template containing N2-methyl-2'-deoxyguanosine catalyzed by the Klenow fragment of Escherichia coli DNA polymerase I.

Formaldehyde is produced in most living systems and is present in the environment. Evidence that formaldehyde causes cancer in experimental animals infers that it may be a carcinogenic hazard to humans. Formaldehyde reacts with the exocyclic amino group of deoxyguanosine, resulting in the formation of N2-methyl-2'-deoxyguanosine (N2-Me-dG) via reduction of the Schiff base. The same reaction is likely to occur in living cells, because cells contain endogenous reductants such as ascorbic acid and gluthathione. To explore the miscoding properties of formaldehyde-derived DNA adducts a site-specifically modified oligodeoxynucleotide containing a N2-Me-dG was prepared and used as the template in primer extension reactions catalyzed by the Klenow fragment of Escherichia coli DNA polymerase I. The primer extension reaction was slightly stalled one base before the N2-Me-dG lesion, but DNA synthesis past this lesion was readily completed. The fully extended products were analyzed to quantify the miscoding specificities of N2-Me-dG. Preferential incorporation of dCMP, the correct base, opposite the lesion was observed, along with small amounts of misincorporation of dTMP (9.4%). No deletions were detected. Steady-state kinetic studies indicated that the frequency of nucleotide insertion for dTMP was only 1.2 times lower than for dCMP and the frequency of chain extension from the 3'-terminus of a dT:N2-Me-dG pair was only 2.1 times lower than from a dC:N2-Me-dG pair. We conclude that N2-Me-dG is a miscoding lesion capable of generating G-->A transition mutations.

Catalysis↗
PubMed2001

FMN is covalently attached to a threonine residue in the NqrB and NqrC subunits of Na(+)-translocating NADH-quinone reductase from Vibrio alginolyticus.

The Na(+)-translocating NADH-quinone reductase (NQR) from Vibrio alginolyticus is composed of six subunits (NqrA to NqrF). We previously demonstrated that both NqrB and NqrC subunits contain a flavin cofactor covalently attached to a threonine residue. Fluorescent peptide fragments derived from the NqrB and NqrC subunits were applied to a matrix-assisted laser desorption ionization time-of-flight mass spectrometer, and covalently attached flavin was identified as FMN in both subunits. From post-source decay fragmentation analysis, it was concluded that FMN is attached by a phosphate group to Thr-235 in the NqrB subunit and to Thr-223 in the NqrC subunit. The phosphoester binding of FMN to a threonine residue reported here is a new type of flavin attachment to a polypeptide.

Amino Acid Sequence↗