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Biomedical subjects

M Tsukamoto

Publications and source records attributed to M Tsukamoto.

At least 73 records · Page 4Linked to original sources
PubMed1996

Negligible synergistic effect of beta2-glycoprotein I on the reactivity of antioxidized low-density lipoprotein antibody to oxidized low-density lipoprotein.

We conducted this study to investigate whether antioxidized low-density lipoprotein (a-oxLDL) is an antibody to cryptic and/or neo-antigen on beta2-glycoprotein I (GPI), which is introduced by binding to anionic phospholipid, similar to that of GPI-dependent anticardiolipin antibody (aCL) employing a-oxLDL ELISA. We found that no significant optical density differences existed among systemic lupus erythematosus patients, including cases with aCL and/or lupus anticoagulant positivity, before and after the addition of GPI. Our results suggest that a-oxLDL is not an antibody to denatured GPI, but rather to oxLDL.

Autoantibodies↗
PubMed1996

Buffer may be the critical factor in measurement of anti-prothrombin antibody on a gamma-ray-irradiated plate by enzyme-linked immunosorbent assay.

We investigated the influence of different buffers (Tris-buffer and phosphate buffered saline (PBS)/Tween-20 buffer) on anti-prothrombin antibody (aPT) measurement by enzyme-linked immunosorbent assay (ELISA), employing a gamma-ray-irradiated plate. We found considerable discrepancies in aPT positivity between each buffer, and we suggest that the use of Tris-buffer is not suitable for aPT measurement with a gamma-ray-irradiated plate to measure aPT.

Autoantibodies↗
PubMed1996

Cytochalasin-E-Resistant Mutants of Coprinus cinereus: Isolation and Genetic, Biochemical, and Cytological Analyses

We first obtained a cytochalasin-E supersensitive strain (CES14) of the basidiomycete Coprinus cinereus and then isolated 1000 revertants of CES14, expecting that at least some of the revertants have defects in the functions of actin filaments. Microscopic examination revealed that three of the revertants lack septa in their hyphae. Of the 1000 revertants, 18 including the 3 septumless strains were genetically analyzed. In 11 of the 18 revertants, reversion was due to extragenic suppressor mutations of ces14. Ten of the 11 mutations were in the same locus designated cer1, while the locus of the remaining mutation, which inhibits septum formation, could not be determined because of its failure to mate with any other cer1 strains. In one (CES14R42) of the cer1 mutants, actin appeared to be altered in the affinity to actin antibody in Western blotting after isoelectric focusing, suggesting that cer1 is a gene encoding actin. Phenotypic examination revealed that the 10 cer1 mutations all confer resistance to cytochalasin-E and that two of the cer1 mutations, both of which block septation, inhibit the formation of the actin ring.

Journal Article↗
PubMed1996

Cyclic motor activity of the gallbladder maintained in a pylorus-preserving gastrectomy in dogs.

The gallbladder has cyclic motor activity (CMA), which is impaired after a conventional gastrectomy. We conducted experiments to determine whether or not a pylorus-preserving gastrectomy (PPG) could maintain gallbladder CMA. Six strain gauge force transducers were implanted into the gastrointestinal tract and gallbladder of six dogs, respectively. The motor activity of the gastrointestinal tract and gallbladder was recorded as a control. PPG was then carried out. The phasic contractions of the gallbladder, which were correlated with the antral contractions in the control state, were synchronized with contractions of the pylorus after PPG. Intravenous administration of CCK-OP (40 ng/kg) induced phasic contractions of the gallbladder at 4.6 +/- 0.2 c/min in 3 of the 6 days with gastric contractions. After PPG, the gallbladder had phasic contractions (4.5 +/- 0.2 c/m), which were synchronized with the contractions of the pylorus in all dogs regardless of the contractions in the remnant stomach. These findings suggest that gallbladder CMa has a closer relationship with the CMA of the pylorus than with the remnant stomach after PPG. Thus, a preservation of the pylorus at the time of gastric surgery will help in maintaining gallbladder function and coordination with the remnant stomach.

Animals↗
PubMed1996

Phosphatidyl serine-dependent antiprothrombin antibody is exclusive to patients with lupus anticoagulant.

We conducted this study to determine whether antiprothrombin antibody (aPT) [to prothrombin (PT) alone or PT/phosphatidyl serine (PS) complex] actually existed in patients with lupus anticoagulant (LA) and/or anticardiolipin antibody (aCL). aPT to PT alone was positive in 2/7 LA-positive (29%) and 3/7 LA/aCL-positive (43%) patients. aPT to PT/PS complex was positive in 4/7 LA-positive (57%) and 4/7 LA/aCL-positive (57%) patients in the presence of Ca2+. However, none of the aCL-positive patients without LA or the LA/aCL-negative patients were positive for aPT and aPT/PS. Thus, we confirmed the existence of aPT and aPT/PS specifically among LA-positive patients. However, the clinicopathological significance of aPT and aPT/PS in this clinical setting is yet to be clarified.

Antibodies, Anticardiolipin↗
PubMed1996

[Effectiveness of LH-RH agonist for bone metastases of breast cancer--report of a case].

A 44-year-old premenopausal woman with bone metastases of breast cancer was initially treated with systemic chemotherapy (CEF) and radiation therapy after standard mastectomy. However, progressive change of bone metastases with elevation of tumor markers (CEA, NCC-ST 439) was detected, so continuous administration of LH-RH agonist and combination chemotherapy (CEF) were conducted. Subsequently, complete objective regression was attained after 40 weeks.

Adult↗
PubMed1996

[Early and late results of surgical intervention for 32 active infective endocarditis patients in last 10 years].

Thirty-two active infectious endocarditis patients who underwent 36 surgical procedures (23 NVEs, 13 PVEs) in last 10 years were reviewed. Seven patients (19.4%) died early postoperatively, 3/23 (13%) in NVEs and 4/13 (31%) in PVEs, and the causes of death were LOS in 5, MOF in one and cerebral bleeding in one. NVE patients of double valve deterioration who developed cardiogenic shock had poor operative results, 3 death in 4 (75%) despite of circulatory assist. Aortic PVEs who underwent Danielson's translocation technique also showed 3 death in 4 (75%). Five in 25 survivors (20%) developed late death and 3 of them were related with reinfection of prosthetic valve. We concluded that surgical treatment for active IE provides reasonable results, although they are still challenging for double valve NVEs and aortic PVEs, for which aortic root replacement using homograft would be the procedure of choice.

Adolescent↗
PubMed1995

Inhibitory activity of anti-beta 2-glycoprotein I antibody on factor Va degradation by activated-protein C and its cofactor protein S.

We investigated the influence of anti-beta 2-glycoprotein I (aGPI), which recently has come to be regarded as anti-cardiolipin antibody (aCL) itself, on factor Va (FVa) degradation by activated protein C/protein S system. We found that aGPI had an inhibitory effect on FVa degradation with beta 2-glycoprotein I-dependency, thus suggesting aGPI/aCL is a highly possible factor as the pathogenesis of thrombosis observed in aGPI/aCL-positive patients.

Animals↗
PubMed1995

Mid-term surgical results after valve replacement with the CarboMedics valve prosthesis.

We present herein a review of 95 patients who underwent valve replacement with the CarboMedics (CM) valve prosthesis between April 1990 and December 1992. The operative mortality for the entire group was 4.2%: 0% following aortic valve replacement (AVR), 2.7% following double valve replacement (DVR). All patients were prescribed warfarin and bucolome for anticoagulation, and were followed up for a mean period of 29.9 months. Late mortality was 8.4%; 3.1% following AVR, 10.8% following MVR, and 12.5% following DVR. There were no cases of mechanical prosthetic valve failure, significant hemolysis, infective prosthetic valve endocarditis, or bleeding complications. After 44 months of follow-up, the actuarial freedom from complications was calculated as: thromboembolism, 97.8 +/- 1.6%; valve thrombosis, 97.8 +/- 1.1%; paravalvular leak, 96.7 +/- 1.9%; and reoperation, 98.9 +/- 1.1%. The overall survival rate was 84.3 +/- 6.3% and all survivors showed a significant improvement in NYHA functional class, from 81% in classes III and IV preoperatively to 99% in classes I and II postoperatively. The CM valve exhibited no significant differences in hemolytic parameters or hemodynamic performance after isolated AVR or MVR compared with the similar type of St. Jude Medical bileaflet valve. The evidence provided by the present study therefore suggests that the CM valve prosthesis can achieve excellent mid-term clinical results and hemodynamic performance with a low incidence of thromboembolism and valve thrombosis.

Adolescent↗
PubMed1995

Color vision and color pattern visual evoked cortical potentials in a patient with acquired cerebral dyschromatopsia.

We examined a 74-year-old man because of difficulty seeing green and the presence of prosopagnosia. His visual acuity was 0.8 in both eyes. He was not congenitally color blind, and there was no family history of color blindness. A left superior homonymous quadrantanopsia was found. The dyschromatopsia ws identical in both eyes. The patient showed red-green deficiency on testing with Ishihara plates a deutan defect with Tokyo Medical College plates, strong blue-yellow defects and medium red-green defects with Standard Pseudochromatic Plates II and a tritan defect with the Panel D-15. He failed the New Color separation test with scores of 160 and could not carry out the Farnsworth-Munsell 100-hue test, but his color naming test results were normal. Visual evoked cortical potentials to black-and-white checkerboard and color pattern reversal (Red and Blue-Green, Green and Red-Purple, Purple and Yellow-Green: isochromatic paired checks) stimuli were normal. Bilateral inferior occipital lesions were found by computed tomography and T2-weighted magnetic resonance imaging. Our findings suggested that luminance and color channels up to area 17 in our patient were intact. We believe that our patient's acquired cerebral dyschromatopsia is rare.

Aged↗
PubMed1995

Gene transfer and expression in progeny after intravenous DNA injection into pregnant mice.

Several methods that enable foreign genes to be transferred directly into germ cells and adult animals have been developed, which have stimulated great interest in manipulating genes in vivo. However, there have been no methods available for introducing genes into fetuses. We report here that a single intravenous injection of expression plasmid: lipopolyamine complexes into pregnant mice resulted in successful gene transfer into the embryos. The transgenes thus introduced were expressed in the fetuses and newborn progeny. This simple and new method of gene transfer into embryos will facilitate rapid analysis of transgene effects in the fetuses and will be useful for studying gene-deficient animal models to gain transgene functions at desired stages of embryogenesis.

Animals↗
PubMed1995

Hst-1 (FGF-4) antisense oligonucleotides block murine limb development.

The initiation of limb development depends on the site specific proliferation of the mesenchyme by the signals from the apical ectodermal ridge (AER) in embryonic mouse. We have previously reported that the local expression of Hst-1/Fgf-4 transcripts in AER of the mouse limb bud is developmentally regulated, expressed at 11 and 12 days post coitus (p.c.) embryo. In an effort to further understand the role of Hst-1/FGF-4 in mouse limb development, an antisense oligodeoxynucleotides (ODNs) study was performed. We first established a novel organ culture system to study mouse limb development in vitro. This system allows mouse limb bud at 9.5-10-d p.c. embryo, when placed on a sheet of extracellular matrix in a defined medium, to differentiate into a limb at 12.5-d p.c. embryo within 4.5 d. Using this organ culture system, we have shown that exposure of 9.5-10-d p.c. embryonal limb bud explants to antisense ODNs of Hst-1/FGF-4 blocks limb development. In contrast, sense and scrambled ODNs have no inhibitory effect on limb outgrowth, suggesting that Hst-1/FGF-4 may work as a potent inducing factor for mouse limb development.

Animals↗
PubMed1995

Resistance to activated protein C activity of an anti-beta 2-glycoprotein I antibody in the presence of beta 2-glycoprotein I.

Some researchers claim that lupus anticoagulant-positive plasma may cause a false-positive reaction in the test for activated protein C (APC) resistance, a hereditary thrombophilic state characterized by abnormal factor V, which frequently causes venous thrombosis. We investigated whether anti-beta 2-glycoprotein I antibody (aGPI), which has recently come to be regarded as an anti-cardiolipin antibody (aCL) itself, might have an effect on the APC resistance test.

Antibodies, Anticardiolipin↗
PubMed1995

Prevalence of beta 2-glycoprotein I antibody in systemic lupus erythematosus patients with beta 2-glycoprotein I dependent antiphospholipid antibodies.

OBJECTIVE: To investigate whether beta 2-glycoprotein I antibody (aGPI) exists in sera that are positive for antiphospholipid antibodies (aPL). METHODS: Thirty six patients with systemic lupus erythematosus (SLE) and 20 healthy volunteers were recruited. GPI independent and dependent aPL (anticardiolipin (aCL), antiphosphatidylserine, antiphosphatidylinositol, antiphosphatidic acid) were measured using a conventional enzyme linked immunosorbent assay (ELISA). aGPI was measured by an ELISA using a gamma irradiated plate coated with purified GPI. RESULTS: Twenty of 36 SLE patients were positive for at least one of the GPI-dependent aPL. Five of these 20 were also positive for aGPI. Another five of the 20 showed low GPI dependency aCL antibodies; however, three of these patients required GPI for binding to phosphatidylserine, phosphatidylinositol, or both. CONCLUSION: We confirmed the existence of aGPI in patients with true GPI dependent aPL. From these results, we recommend the use of a gamma irradiated plate with GPI as antigen for the detection of true GPI dependent aPL or aGPI.

Antibodies, Anticardiolipin↗
PubMed1995

Effective prevention of thrombocytopenia in mice using adenovirus-mediated transfer of HST-1 (FGF-4) gene.

HST-1 (FGF-4) gene product is a member of the fibroblast growth factor family with a signal peptide and plays a crucial role in limb development. We showed previously that an intraperitoneal injection of replication-deficient adenovirus containing the HST-1 gene (Adex1HST-1) into normal mice caused a twofold increase in peripheral platelet count. To investigate whether Adex1HST-1 could effectively prevent experimentally induced thrombocytopenia in mice, we injected Adex1HST-1 intraperitoneally into thrombocytopenic mice induced by administration of a chemotherapeutic agent and/or by irradiation. A single Adex1HST-1 injection caused continuously increased levels of serum HST-1 protein for at least 30 d and increased the count of large megakaryocytes in bone marrow, which specifically recovered platelet counts and more efficiently diminished the extent and duration of thrombocytopenia than any other reported cytokine or any combination of cytokines so far. In the other peripheral hematological parameters, no discernible differences were detected. No other apparent side effects were observed. Therefore, this method could be useful for treatment and/or prevention of thrombocytopenia induced by chemotherapy and/or irradiation for cancer treatment.

Adenoviruses, Human↗
PubMed1995

Purification and characterization of glutathione-independent denitration enzyme of organic nitrate esters in rabbit hepatic cytosol.

The enzyme responsible for glutathione (GSH)-independent denitration of organic nitrate esters was purified by gel chromatography, ion-exchange chromatography and affinity chromatography from rabbit hepatic cytosol. The enzyme showed a molecular mass of 175 kDa and consisted of three subunits of 59 kDa. The enzyme exerted its maximum activities at around pH 9, when isosorbide dinitrate (ISDN) was used as substrate. The enzyme possessed a low Km value (10(-6) M) for various organic nitrate esters. The present enzyme is likely to be involved in the denitration of organic nitrate esters in conjunction with known enzymes, GSH S-transferase (GST) and cytochrome P450.

Ammonium Sulfate↗
PubMed1995

High prevalence of anti-phospholipid antibodies and anti-thyroglobulin antibody in patients with hepatitis C virus infection treated with interferon-alpha.

OBJECTIVES AND METHODS: We investigated the prevalence rate of beta 2-glycoprotein I (beta 2-GPI)-dependent antiphospholipid antibodies (aPL)[anti-cardiolipin antibody (aCL), anti-phosphadidylserine antibody (aPS), and anti-phosphatidic acid antibody (aPA)], antinuclear antibody (ANA), anti-deoxyribonucleic acid antibody (aDNA), anti-thyroglobulin antibody (aTG), and anti-thyroid peroxidase antibody (aTPO) in 56 patients with hepatitis C virus (HCV) infection and correlated the results with inteferon-alpha (IFN) treatment. RESULTS: aCL, aPS, and aPA were positive in, respectively, 7/56 (13%), 12/56 (21%), and 13/56 (23%) patients before treatment. aPS and aPA appeared in 6/44 and 9/43 and disappeared in 6/12 and 2/13 patients, respectively, after IFN treatment; the differences were statistically significant. The changes in OD readings were higher in the group of patients who became positive for aPS and aPA than in those who became negative after treatment. The positive rates of aTG and aTPO in the patient group were statistically higher than in the healthy controls, and aTG developed in four patients and disappeared in two. No obvious changes in aTPO were observed; however, the aTPO titer was increased in four previously positive patients. None of the patients positive for any antibodies developed an abnormality associated with these antibodies during an observation period of up to 1 yr. CONCLUSIONS: The pathogenesis of production and clinical significance of aPL, ATG/aTPO in this clinical setting are unclear, but immunological disturbances, such as the effects of HCV infection and/or IFN treatment, were considered to be a possibility. Further investigation is needed to clarify whether HCV/aPL- and/or aTG/aTPO-positive patients treated with IFN might develop aPL-associated complications and/or autoimmune disease(es), in the future and to confirm whether IFN treatment justifies the outcome in this clinical setting.

Adult↗