Search PubMed⌕ Search

Biomedical subjects

H Masuda

Publications and source records attributed to H Masuda.

At least 235 records · Page 13Linked to original sources
PubMed1996

Automated fetal breathing movement detection from internal small displacement measurement.

We have previously proposed a method to measure small displacements of internal tissue which is based on an ultrasonic pulsed Doppler technique. The Doppler frequency shift of the ultrasonic waves due to the tissue movement is detected using a modified quadrature detector, and the displacement of the internal tissue is estimated by using an arctangent method. Based on the algorithm, we have constructed a quantitative monitoring system for fetal breathing movement. The fetal breathing movement is a rhythmic movement of the fetal diaphragm and it is recorded as a nearly sinusoidal displacement with a repetition frequency from 0.5 Hz to 2 Hz. In this paper, an automated fetal breathing movement detection algorithm for the displacement data observed by using the small displacement measurement system is proposed. This method uses a modified autocorrelation technique for detecting the displacement due to the fetal breathing movement. The method is applied to five fetuses of late pregnancy and the result is compared with the manual detection.

Algorithms↗
PubMed1996

[A case of secondary leukemia in anaplastic seminoma patient treated with long-term chemotherapy].

A 46-year-old man had received a long-term induction plus salvage chemotherapy for anaplastic seminoma with stage IV disease. Chemotherapy regimens and cycles included the following; four cycles of bleomycin plus vinblastine plus cisplatin (BVP); eight cycles of cyclophosphamide, vincristine, and cisplatin (COP); three cycles of etoposide plus cisplatin (EP); thirteen cycles of etoposide with ifosfamide and cisplatin (VIP). The total cumulative dose of etoposide was 4250 mg/m2. Severe and persistent pancytopenia developed 32 months after starting etoposide-based salvage chemotherapy. Bone marrow examination showed hypercellular marrow containing 68% myeloblasts but peroxidase reaction was negative. CD-13 was 30.1% which meant that leukemia was myelogenous. Therefore, he was diagnosed as acute myelogenous leukemia. French-American-British classification was MO. Chromosome analysis revealed a t (8; 21)(q22;q22) cytogenetic abnormality. This case may be compatible with the clinical and cytogenetic characters of epipodophyllotoxin-related leukemia. We conclude that high doses of etoposide seem to be leukemogenic. To our knowledge, this is the first reported case in the literature relevant to epipodophyllotoxin-related secondary leukemia in testicular tomor in Japan.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

[A case of ASD with SLE treated with Carmeda BioActive surface circuit in cardiopulmonary bypass system].

A 61-year-old woman of ASD complicated with SLE was operated on. We used a heparin coating Carmeda BioActive Surface (CBS) in cardiopulmonary bypass circuit for the purpose to prevent the postoperative complications due to the reduced complement activation by SLE. This system could prevent the decline of the reduced complement activation during cardiopulmonary bypass and after operation. The management of steroid therapy for SLE patient, usefulness of heparin coating CBS system for hypocomplement disease were discussed.

Anti-Inflammatory Agents↗
PubMed1996

Usage of T cell receptor (TCR) V beta gene in ulcerative colitis.

Ulcerative colitis (UC) is an inflammatory disease of unknown etiology. In this study, the expression of TCRV beta gene in UC patients was examined. The present study included 11 consecutive Japanese patients with UC. The control group comprised 10 healthy people. The usage of T Cell Receptor (TCR) V beta chain gene segments in peripheral blood was examined using RT-PCR. In addition, HLA-DR DNA typing was performed for the 11 patients with UC. The average of the positive expression rates in the UC group was 0.617 +/- 0.126, which was significantly higher than that of the control group (0.829 +/- 0.080) (p < 0.01). In the UC group, the usage of V beta chain gene in the active phase was almost same as that in the inactive phase. No specific distribution of V beta repertoire was observed in the UC group. In UC patients, no distinct correlation was found between any certain HLA-DR type and TCRV B gene usage. UC patients had a significantly lower rate of the expression of TCR V beta genes compared to normal controls. There is a possibility that the restricted usage of TCR V beta repertoire is possibly related to the existence of oligoclonal TCR repertoire in UC patients.

Colitis, Ulcerative↗
PubMed1995

Antioxidant role of Rhodnius prolixus heme-binding protein. Protection against heme-induced lipid peroxidation.

Heme in aqueous solutions actively promotes free radical reactions leading to degradation of biological molecules. The blood-sucking insect Rhodnius prolixus has a heme-binding protein (RHBP) in its hemolymph (Oliveira, P.L., Kawooya, J.K., Ribeiro, J.M.C., Meyer, T., Poorman, R., Alves, E.W., Walker, F., Padovan, G.J., and Masuda, H. (1994) J. Biol. Chem. 270, 10897-10901. Here we show that this protein inhibits heme-dependent peroxidation of both linolenic acid liposomes and lipophorin, the main lipoprotein of insect hemolymph. The oxidized lipophorin is functionally impaired, being defective both in its capacity to be loaded with phospholipids from the fat body as well as in its ability to deliver phospholipids to the growing oocytes. RHBP prevents the heme-induced oxidative damage to lipophorin. It is proposed that in vivo RHBP binds the heme derived from digestion of blood hemoglobin, suppressing the generation of activated oxygen species and protecting the insect against oxidative stress throughout the feeding cycle.

Adipose Tissue↗
PubMed1995

Loading of lipophorin particles with phospholipids at the midgut of Rhodnius prolixus.

32P-Labelled midguts (32P-midguts) of Rhodnius prolixus females were incubated in the presence of nonradioactive purified lipophorin and the release of radioactivity to the medium was analysed. The radioactivity found in the medium was associated with lipophorin phospholipids. When the 32P-midguts were incubated in the absence of lipophorin, no 32P-phospholipids were found in the medium. Comparative analysis by thin-layer chromatography of 32P-phospholipids derived from metabolically labelled 32P-midgut or lipophorin particles after incubation with 32P-midgut showed some differences, revealing a possible selectivity in the process of phospholipids transfer. The transfer of phospholipids to lipophorin was linear with time up to 45 min, was saturable with respect to the concentration of lipophorin, and was half-maximal at about 5 mg/ml. The binding of 32P-lipophorin to the midgut at 0 degrees C reached the equilibrium at about 1 h of incubation. The binding of 32P-lipophorin was inhibited by an excess of nonradioactive lipophorin, which suggests a specific receptor for lipophorin. The capacity of midguts and fat bodies to transfer phospholipids to lipophorin varied during the days following the meal. When lipophorin enzymatically depleted of phospholipids by treatment with phospholipase A2 was incubated with 32P-midguts, the same amount of phospholipids was transferred, indicating a net gain of phospholipids by the particle.

Animals↗
PubMed1995

The formation and functioning of yeast mitotic spindles.

The mitotic spindle contains the machinery responsible for sister chromatid segregation. It is composed of a complex and dynamic array of microtubules, which are nucleated from the spindle poles. Studies of yeast spindle functions by molecular genetic analysis and by in vitro functional analysis have identified proteins that are mitosis-specific and present at very low concentrations in the cell, and have revealed the molecular bases of several processes required for the formation and functioning of the mitotic spindle. Here I review the current knowledge of the processes that are common to most eukaryotes: microtubule nucleation at the spindle poles, bipolar spindle assembly, maintenance of the spindle structure, chromosome attachment to the spindle and chromosome separation on the spindle.

Saccharomyces cerevisiae↗
PubMed1995

Antimicrotubule effects of the novel antitumor benzoylphenylurea derivative HO-221.

The antitumor action of HO-221, a novel benzoylphenylurea derivative, was studied. The in vitro cytotoxic strength of HO-221 was investigated, as measured by IC50 values, compared with those of other drugs with different action mechanisms, using Chinese hamster lung (CHL) cells, mouse leukemia L1210 cells and human promyelocytic leukemia HL-60 cells. Morphological alterations following treatment were observed under a phase contrast microscope, and the mitotic index was determined at regular intervals to check for accumulation of metaphase cells. HO-221 was found to have a very strong toxic effect on all cell types, equal to that of the spindle poisons used as controls. HO-221 also produced the same specific morphological changes as the spindle poisons, with a significant accumulation of metaphase cells. A chromosome analysis of treated cells showed that HO-221 frequently induced polyploid and aneuploid cells, but without accompanying chromosome-breaking activity. An in vivo mouse bone marrow micronucleus assay was also carried out. The assay allowed the in vivo identification of a chromosome breaker or a spindle poison through the measurement of the relative sizes of micronuclei produced and erythrocytes. HO-221 was found frequently to induce relatively large micronuclei, an action regarded as specific to spindle poisons. It was thus demonstrated that HO-221 acts as a spindle poison both in vitro and in vivo. In order to investigate the mechanism of this action, a study of tubulin assembly using purified calf brain tubulin was carried out, which demonstrated clearly that HO-221 inhibits microtubule assembly. A detailed investigation of the action mechanism of HO-221 as a spindle poison is now called for.

Animals↗
PubMed1995

Long openings of calcium channels in fetal rat ventricular cardiomyocytes.

Whole-cell and single-channel Ca2+ currents (ICa) of single fetal (12-18 days) and neonatal (1-10 d) rat ventricular myocytes were recorded using patch clamp techniques. Whole-cell ICa density increased markedly during the fetal period and remained almost constant during the neonatal period. In cell-attached patch recordings (with 110 mM Ba2+ in the pipette), the L-type Ca2+ channels, observed on both fetal d-12 and neonatal d 5, had the same conductance (23 pS). On fetal d-12, many relatively long openings were observed in addition to brief openings, whereas on neonatal d-5, long openings were less observed and brief openings dominated. Therefore, long openings of the Ca2+ channels occur in early development in rat heart cells, similar to that reported for chick hearts [7, 8]. The increase of the whole-cell current amplitude observed during development may be due to an increase in available channel number.

Age Factors↗
PubMed1995

Analysis of biological function of poly(ADP-ribosyl)ation in Drosophila melanogaster.

To understand the biological function of poly(ADP-ribosyl)ation of proteins, we have isolated and characterized the gene for poly(ADP-ribose) polymerase from Drosophila melanogaster. Two approaches were taken to analyze the function of the poly(ADP-ribosyl)ation reaction. The first is analysis of the homology of the amino acid sequences of poly(ADP-ribose) polymerase from phylogenetically different eukaryotes, namely human, mouse, bovine, chicken, Xenopus laevis and Drosophila melanogaster and elucidation of the conserved amino acid sequences that appear to be important for the function of poly(ADP-ribose) polymerase. Analysis of the recombinant poly(ADP-ribose) polymerase which had truncated or mutated motifs expressed in E coli would confirm the importance of the conserved amino acid sequence. The interaction of poly(ADP-ribose) polymerase with other proteins involved in DNA repair, replication, recombination and transcription will clarify the function of poly(ADP-ribosyl)ation. The second approach is to get the mutants which have disruption in the poly(ADP-ribose) polymerase gene and to analyse the phenotypes of these mutants. The characterization of these mutants will be discussed.

Amino Acid Sequence↗
PubMed1995

Identification of the antithrombin III Kyoto mutation by restriction fragment length polymorphism analysis.

Clarification of the molecular biologic abnormality underlying antithrombin III (AT III) deficiency is important to a complete understanding of the coagulation system. We have reported previously the deficiency of AT III Kyoto in which there has been a single substitution of thymine for guanine at codon 406 of exon VI. This results in the amino acid substitution of methionine for arginine. The nucleotide substitution at codon 406 in the mutant allele eliminates a Hae III restriction site. Accordingly, Hae III restriction analysis of the PCR fragments in this family could segregate the deficient members from the normal members, enabling the detection of the existence of Hae III restriction fragment length polymorphism of the PCR product (PCR-RFLP). Moreover, we confirmed by direct DNA sequencing with the polymerase chain reaction that the tested deficient members in an AT III Kyoto family inherit the same type of mutation in their genes. In conclusion, Hae III PCR-RFLP can be a useful method for screening of this mutant gene in the family.

Adult↗
PubMed1995

Thyroid abnormalities among children in the contaminated area related to the Chernobyl accident.

Gradual increases of various radiation-related diseases including thyroid cancer following the Chernobyl accident have been recently reported. We have carried out systematic thyroid surveys in school children aged 10-15 years in the highly contaminated area and compared the results with a similar survey in a nonaffected neighboring area as a control. Systematic examinations of the thyroid gland were performed in 888 schoolchildren (408 males and 480 females) in the districts of Chechelsk city with 5 to over 40 Ci/km2 of radiation level for 137Cs. In the control area (Bobruisk city), 521 children with the same age range (229 males and 292 females) were examined. Thyroid surveys were carried out as follows: palpation, ultrasonography, blood examinations of thyroid function, and measurements of daily urinary excretion of iodine. Certain thyroid abnormalities were observed in the high radioactive fallout area more frequently than in the control region. In particular, the prevalence of multiple micronodular lesions in diffuse goiter in the contaminated area was significantly higher than in the control area. However, endemic goiter due to iodine deficiency was present in both districts. The environment factor of iodine deficiency might have resulted in the early occurrence of ultrasonographic thyroid abnormalities attributed to radioactive contamination.

Adolescent↗
PubMed1995

Hemolytic anemia following high-dose intravenous immunoglobulin administration.

We describe two cases of hemolytic anemia following high-dose intravenous human immunoglobulin administration in young females with idiopathic thrombocytopenic purpura. Inducement of hemolytic anemia by anti-A and anti-B antibodies in these cases necessitates the performance of a minor crossmatching procedure prior to immunoglobulin use to prevent the occurrence of this adverse reaction.

Anemia, Hemolytic↗
PubMed1995

[Protective effect of human macrophage colony-stimulating factor on fungal infection (2). In vitro effect of human macrophage colony-stimulating factor on systemic aspergillosis and in vitro effect on the activities of macrophage].

We studied the protective effect of human macrophage colony-stimulating factor (M-CSF) of fungal infection due to systemic aspergillosis in normal mice. We also examined the effect of M-CSF against the activities of mouse peritoneal macrophage which were relating to the phagocytosis, the killing, the production of superoxide after contacting with phorbol myristate acetate and the production of nitric oxide after contacting with interferon-gamma in vitro. M-CSF improved the median survival time and the survival rate of systemic aspergillosis. Combination therapy with M-CSF and amphotericin-B (AMPH-B) showed the therapy with either M-CSF or AMPH-B alone. M-CSF enhanced the activities of phagocytosis and the killing of ingested Candida albicans H and spores of Aspergillus fumigatus K by macrophage. Furthermore, M-CSF promoted the production of superoxide and nitric oxide in macrophage. These results indicate that M-CSF can enhance the fungicidal activity of macrophages by activation in vivo, thereby preventing the dissemination of fungal infection.

Amphotericin B↗
PubMed1995

[Protective effect of human macrophage colony-stimulating factor (hM-CSF) on fungal infection (1). In vivo effect of hM-CSF on systemic candidiasis and in vitro effect of hM-CSF on macrophages activities].

We studied the protective effect of human macrophage colony-stimulating factor (hM-CSF) on fungal infection due to systemic candidiasis in vivo and the activities of macrophages in vitro, in order to demonstrate the usefulness of M-CSF on fungal infection. The effect of hM-CSF on systemic candidiasis was examined by using normal and immunosuppressed mice. In addition, the effects of hM-CSF on the activity of reticuloendothelial system (RES) organ and on the phagocytic activity and NBT reduction activity of mouse macrophage were also examined in vitro. HM-CSF improved the survival rate of systemic candidiasis in both normal and immunosuppressed mice. Combination therapy with hM-CSF and fluconazole showed higher survival rate more than in the therapy with either hM-CSF or fluconazole alone. Furthermore, hM-CSF enhanced the activity of RES organ, phagocytosis by macrophages and NBT reduction by macrophages, significantly. These results indicate that hM-CSF enhances the phagocytic cactivity and candicidal activity by macrophages in vivo, thereby preventing dissemination of fungal infection.

Animals↗
PubMed1995

Studies on the preparation of bioactive lignans by oxidative coupling reaction. VI. Oxidation of methyl (E)-3-(4,5-dihydroxy-2-methoxyphenyl)-2-butenoate and lipid peroxidation-inhibitory effects of the produced caffeoquinone.

Oxidation of hydroxy-alpha-methylcinnamate 5 derived from 4-methylesculetin afforded the alpha-methylcaffeoquinone derivative 7 without formation of the oxidative coupling product. The reaction of the alpha-methylferulate derivative 13 afforded a complex mixture of products. Thus, the hydroxy-alpha-methylcinnamates seem not to be suitable substrates for oxidative coupling. Compound 7 was tested for inhibitory effect on lipid peroxidation. It showed more potent activity than idebenone in rat brain homogenate, and was much more potent than (+/-)-alpha-tocopherol in rat liver microsomes.

Animals↗