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M Masuko

Publications and source records attributed to M Masuko.

At least 19 recordsLinked to original sources
PubMed2001

Receptor specificity in the self-renewal and differentiation of primary multipotential hemopoietic cells.

To determine whether cytokine-induced signals generate unique responses in multipotential hemopoietic progenitor cells, the signaling domains of 3 different growth factor receptors (Mpl, granulocyte-colony-stimulating factor [G-CSF] receptor, and Flt-3) were inserted into mouse primary bone marrow cells. To circumvent the activation of endogenous receptors, each signaling domain was incorporated into an FK506 binding protein (FKBP) fusion to allow for its specific activation using synthetic FKBP ligands. Each signaling domain supported the growth of Ba/F3 cells; however, only Mpl supported the sustained growth of transduced marrow cells, with a dramatic expansion of multipotential progenitors and megakaryocytes. These findings demonstrate that the self-renewal and differentiation of multipotential progenitor cells can be influenced through distinct, receptor-initiated signaling pathways.

Animals↗
PubMed2001

Erythroid involvement in CD36 deficiency.

OBJECTIVE: The CD36 molecule is expressed in platelets, monocytes, erythroblasts, and other different tissues. The two types of platelet CD36 deficiency, types I and II, are associated with the absence and presence of CD36 on monocytes, respectively. To clarify the involvement of the erythroid lineage in CD36 deficiency, we investigated the phenotype and RNA expression of CD36. MATERIALS AND METHODS: CD36 expression was examined in 296 patients with several cardiovascular diseases in our outpatient clinic. There were 12 patients with type I deficiency and 16 with type II CD36 deficiency. A bone marrow sample was examined in five type I and four type II patients. Expression of CD36 mRNA was examined in burst-forming unit-erythroid (BFU-E). The sequences of reverse transcriptase polymerase chain reaction (RT-PCR) products of the CD36 mRNA from monocytes were examined. RESULTS: As expected, CD36 was deficient in erythroblasts from all five patients with type I deficiency. CD36 was present in erythroblasts from three of the four with type II deficiency, suggesting that their abnormality is restricted to platelets (type IIa). CD36 was unexpectedly absent from erythroblasts of a single type II patient (type IIb). CD36-specific mRNA was identified in BFU-E from each of two normals, six type I, and six type II patients, including type IIb. The sequences of RT-PCR products of the CD36 mRNA in a patient with type IIa and another with type IIb showed homozygous wild alleles. CONCLUSION: The findings provide evidence for further heterogeneity among CD36-deficient individuals and the existence of a basic principle mechanism of type II, such as glycosylation abnormality.

Angina Pectoris↗
PubMed2001

[Panic disorder and antidepressants].

Anxiety disorders, specifically, panic disorder, are the most common mental health disorders. Unless the clinician has a high index of suspicion, panic disorder or social anxiety disorder may remain undetected. Although quality of life(QOL) issues have long been recognized in severe psychiatric disorders, they have only recently come to be considered for the anxiety disorders. While the older tricyclic antidepressants(TCAs) are efficacious in the treatment of theses anxiety disorders, recent studies with paroxetine and other selective serotonin reuptake inhibitors(SSRIs) have emphasized the role of serotonin in the aetiology of these conditions. Both the TCA and SSRI antidepressants are effective in treating a wide variety of anxiety disorders. SSRIs, due to their greater safety and tolerability, should be the preferred choices in treating anxiety disorders in those instances.

Antidepressive Agents, Tricyclic↗
PubMed2000

Fluorescence resonance energy transfer from pyrene to perylene labels for nucleic acid hybridization assays under homogeneous solution conditions.

We characterized the fluorescence resonance energy transfer (FRET) from pyrene (donor) to perylene (acceptor) for nucleic acid assays under homogeneous solution conditions. We used the hybridization between a target 32 mer and its complementary two sequential 16 mer deoxyribonucleotides whose neighboring terminals were each respectively labeled with a pyrene and a perylene residue. A transfer efficiency of approximately 100% was attained upon the hybridization when observing perylene fluorescence at 459 nm with 347-nm excitation of a pyrene absorption peak. The Förster distance between two dye residues was 22.3 A (the orientation factor of 2/3). We could change the distance between the residues by inserting various numbers of nucleotides into the center of the target, thus creating a gap between the dye residues on a hybrid. Assuming that the number of inserted nucleo-tides is proportional to the distance between the dye residues, the energy transfer efficiency versus number of inserted nucleotides strictly obeyed the Förster theory. The mean inter-nucleotide distance of the single-stranded portion was estimated to be 2.1 A. Comparison between the fluorescent properties of a pyrene-perylene pair with those of a widely used fluorescein-rhodamine pair showed that the pyrene-perylene FRET is suitable for hybridization assays.

DNA, Bacterial↗
PubMed2000

The coxsackievirus-adenovirus receptor protein as a cell adhesion molecule in the developing mouse brain.

In an attempt to elucidate the molecular mechanisms underlying neuro-network formation in the developing brain, we analyzed 130 proteolytic cleavage peptides of membrane proteins purified from newborn mouse brains. We describe here the characterization of a membrane protein with an apparent molecular mass of 46 kDa, a member of the immunoglobulin superfamily of which the cDNA sequence was recently reported, encoding the mouse homologue of the human coxsackievirus and adenovirus receptor (mCAR). Western and Northern blot analyses demonstrated the abundant expression of mCAR in the mouse brain, the highest level being observed in the newborn mouse brain, and its expression was detected in embryos as early as at 10. 5 days post-coitus (dpc), but decreased rapidly after birth. On in situ hybridization, mCAR mRNA expression was observed throughout the newborn mouse brain. In primary neurons from the hippocampi of mouse embryos the expression of mCAR was observed throughout the cells including those in growth cones on immunohistochemistry. In order to determine whether or not mCAR is involved in cell adhesion, aggregation assays were carried out. C6 cells transfected with mCAR cDNA aggregated homophilically, which was inhibited by specific antibodies against the extracellular domain of mCAR. In addition to its action as a virus receptor, mCAR may function naturally as an adhesion molecule involved in neuro-network formation in the developing nervous system.

Amino Acid Sequence↗
PubMed2000

Expression of coxsackievirus and adenovirus receptor in hearts of rats with experimental autoimmune myocarditis.

The expression of coxsackievirus and adenovirus receptor (CAR) was dominant in the brains and hearts of mice until the newborn phase. There is no detailed information concerning the relation between the expression of CAR and development of hearts. It is also uncertain whether CAR is able to be induced in adult hearts after cardiac injury. We demonstrated that CAR was abundant in the hearts of newborn rats but was barely detectable in the hearts of adult rats. The expression of CAR in rat hearts with experimental autoimmune myocarditis, which was induced by immunization of purified cardiac myosin, was serially investigated. Active myocarditis was observed from day 15 after immunization. By immunohistochemistry, cardiomyocytes were strongly stained for CAR antibody from days 24 to 42. CAR mRNA was also detected from days 18 to 30 by using reverse transcription-polymerase chain reaction. In the next experiment, the induction of CAR on isolated cardiomyocytes was investigated. CAR was barely detectable in cultured cardiomyocytes by Western blot analysis after isolation. This molecule gradually appeared along with the creation of clusters and beating of cardiomyocytes. Furthermore, the induction of CAR in cultured cardiomyocytes increased after supplement with conditioned medium of rat splenocytes activated by concanavalin A. In conclusion, rat CAR is expressed strongly in the hearts of newborn rats and is suppressed in those of adult rats. The expression of CAR is enhanced during the active phase of experimental autoimmune myocarditis and is induced by inflammatory mediators. CAR may play a role in cell-to-cell contact and adhesion of cardiomyocytes.

Aging↗
PubMed2000

Cyclosporine A-associated fatal central nervous system angiopathy in a bone marrow transplant recipient: an autopsy case.

We report here the case of a 32-year-old woman who suffered from a unique angiopathy in the central nervous system (CNS). She died of multiple infarcts in the brain stem and cerebellum during treatment with cyclosporine A after bone marrow transplantation for refractory anemia with excess of blasts. The autopsy findings showed segmental narrowing of the basilar artery, in which circumferential dissection of the internal elastic lamina had occurred. The distal portion of the basilar artery was obstructed by upward dislocation of the dissected intima. Similar angiopathy was also observed at multiple sites along the basilar artery branches. These findings suggest endothelial damage, including vasoconstriction and dissection of the CNS arteries.

Adult↗
PubMed2000

Dynamics of the fluorescence properties of pyrene residues appended to oligonucleotide hybridization probes.

The dynamic and static properties of the fluorescence of a pyrene-introduced oligonucleotide 16 mer and its hybrid with a target 32 mer. Their fluorescence quantum yields (< 1%) were much weaker than that of unsubstituted pyrene and their fluorescence lifetime of the major decay components were less than 1 ns. The rapid fluorescence quenching was due to the interaction between the fluorophore and bases in the oligonucleotides. The fluorescence of pyrene was quenched efficiently by TMP and slightly by AMP. The quenching by CMP and GMP were the intermediate case.

Adenosine Monophosphate↗
PubMed1999

Novel technique for the direct flow cytofluorometric analysis of human basophils in unseparated blood and bone marrow, and the characterization of phenotype and peroxidase of human basophils.

BACKGROUND: No technique has been reported to analyze directly the antigen expression on basophil leukocytes when using a flow cytometer; therefore, the exact phenotype of human basophils and the character of the peroxidase in basophils are not well understood. METHODS: Human blood basophils were purified by using an antibody against high-affinity Fc epsilon receptor (hFcepsilonR) and a MACS magnetic cell sorting system and then cytochemically stained. The phenotype and peroxidase of the human basophils were flow cytofluorometrically analyzed directly in unseparated blood and bone marrow samples as hFcepsilonR+/MBP+ (major basic protein)/Hist+ (histamine) light-density cells distributed in the high sidescatter area of lymphocytes on light scattergrams. RESULTS: The peroxidase granules of human basophils were stained by an anti-eosinophil peroxidase (EPO) antibody. The human blood basophils had common granulocyte markers plus CD25, i.e., they were CD11a/ CD11b/CD11c/CD25/CD38/CD13/CD33/hFcepsi lonR/MBP/Hist/ EPO positive, CD71 dim positive, CD14/CD15 partially positive, and CD2/CD3/CD7/CD122/CD16/CD56/CD57/ CD10/CD19/CD20/CD22/HLA-DR/MPO (myeloperoxidase)/CD23 negative. Further examination was done to analyze the expression of colony-stimulating factor receptors on three lineages of granulocytes, i.e., basophils, eosinophils, and neutrophils. The neutrophils were CD114 (G-CSFR)/CD116 (GM-CSFR)/CD124 [interleukin (IL)-4R]/CD126 (IL-6R) positive and CD123 (IL-3R)/CD125 (IL-5R) negative. In contrast, the eosinophils and basophils were CD116/CD123/CD125/CD126 positive and CD114/CD124 negative. CONCLUSIONS: This novel technique for directly characterizing human basophil leukocytes with flow cytometry may be a convenient way to screen the expression of surface antigens and the cytoplasmic expression of CD antigens and other proteins in human blood basophils and to analyze alterations of the character of basophils by cytokines and other biological substances in vivo and in vitro.

Adult↗
PubMed1999

Expression of eosinophil peroxidase in the immature basophil cell line KU812-F.

Although peroxidase activity in basophils can be detected by optical and ultrastructural cytochemistry, its characteristics remain to be determined. We have demonstrated the characteristics of peroxidase activity induced in the immature basophil cell line, KU812-F. Ultrastructurally, peroxidase activity was detected in granules as well as in the perinuclear space and endoplasmic reticulum. Immunocytochemistry revealed that KU812-F cells were stained by anti-eosinophil peroxidase antibodies, and eosinophil peroxidase mRNA, not myeloperoxidase, was detected in the cells using Northern hybridization and reverse transcription-polymerase chain reaction. Eosinophil peroxidase can be one of the molecules shared with eosinophils and basophils. The biological function of eosinophil peroxidase detected in basophils remains uncertain.

Basophils↗
PubMed1998

Optimization of excimer-forming two-probe nucleic acid hybridization method with pyrene as a fluorophore.

A previously presented homogeneous assay method, named the excimer-forming two-probe nucleic acid hybridization (ETPH) method, is based on specific excimer formation between two pyrenes attached at the neighboring terminals of two sequential probe oligonucleotides complementary to a single target. In this study, we investigated assay conditions and optimal molecular design of probes for intense excimer emission using a pyrenemethyliodoacetamide-introduced 16mer probe, a pyrene butanoic acid-introduced 16merprobe and a target 32mer. The length of the linker between the pyrene residue and the terminal sugar moiety remarkably influenced the quantum efficiency of excimer emission; the pair of linker arms of these two probes was optimal. The quantum efficiency was also dependent upon the concentrations of dimethylformamide and NaCl added to the assay solution. Spectroscopic measurements and T m analysis showed that an optimal configuration of the two pyrene residues for intense excimer emission might be affected by pyrene-pyrene interaction, pyrene-duplex interaction (intercalation/stacking) and solvent conditions as a whole. We then demonstrated the practicality of the ETPH method with the optimal hybridization conditions thus attained by determining that the concentration of 16S rRNA in extracts from Vibrio mimicus ATCC 33655 cells in exponential growth phase is 18 500 16S rRNA molecules/cell on average.

Absorption↗
PubMed1998

Transcriptional activation of the alternative oxidase gene of the fungus Magnaporthe grisea by a respiratory-inhibiting fungicide and hydrogen peroxide.

Alternative oxidase (AOX) is dramatically induced when the fungus Magnaporthe grisea is incubated with the fungicide SSF-126, which interacts with the cytochrome bc1 complex in the electron transport system of mitochondria. A full-length cDNA for the alternative oxidase gene (AOX) was obtained, and the deduced amino acid sequence revealed marked similarity to other AOXs, but lacks two cysteine residues at corresponding sites which are conserved in plant AOXs and play essential roles in the post-translational regulation. Northern blot experiments showed that treatment of M. grisea cells with SSF-126 induces accumulation of AOX mRNA in a dose-dependent manner, and the level was correlated with the activity of alternative respiration. H2O2 also induced the accumulation of the transcript with a short half-life (<15 min). Nuclear run-on experiments showed that the AOX gene was transcribed constitutively in unstimulated cells. Cycloheximide did not change the basal level of transcription, but induced the accumulation of the transcript, indicating that active degradation of the transcript occurs by factor(s) sensitive to cycloheximide. On the other hand, SSF-126 enhanced the transcriptional activity of AOX gene threefold compared to that of control cells, and H2O2 was also potent for enhancement of the transcription. From these results, it is concluded that the respiratory inhibitor-dependent activation of the transcription is a primary determinant for the induction of alternative respiration in M. grisea. Because we have previously shown that SSF-126 treatment of M. grisea mitochondria induced the generation of superoxide, active oxygen species are thought to be signal mediators to activate AOX gene transcription in M. grisea.

Amino Acid Sequence↗
PubMed1998

Hematopoietic cytokine-dependent differentiation to eosinophils and neutrophils in a newly established acute promyelocytic leukemia cell line with t(15;17).

We recently established an acute promyelocytic leukemia (APL) cell line (HT93) that has the capacity to differentiate into neutrophils and eosinophils in response to all-trans retinoic acid (ATRA) and human hematopoietic cytokines. The cells had a myeloblastic morphology, were positive for surface CD33, CD34, and CD56, and showed the following karyotypes: 46, XY, t(1;12)(q25;p13), 2q+, t(4;6)(q12;q13), and t(15;17)(q22;q11). When the cells were cultured with ATRA, they showed nuclear segmentation and developed secondary granules consisting in part of neutrophils and eosinophils. In the presence of ATRA and granulocyte colony-stimulating factor (G-CSF), the cells showed polymorphonuclear neutrophil differentiation accompanied by expression of surface CD11b, CD15, CD10, positive activity for neutrophil alkaline phosphatase (NAP), and NAP mRNA expression. In cultures with ATRA and granulocyte-macrophage colony-stimulating factor (GM-CSF), IL (interleukin)-3, or IL-5, HT93 showed remarkable eosinophil maturation at day 8 as determined by luxol fast blue staining, in addition to expression of eosinophil peroxidase and major basic protein. These results indicate that HT93 is an APL cell line with the ability to differentiate into neutrophils and eosinophils, and that these lineages are dependent on the CSF added. HT 93 should prove to be a useful model in analyzing the effects of hematopoietic cytokines on proliferation, differentiation, and maturation of hematopoietic progenitors.

Alkaline Phosphatase↗
PubMed1997

Serum protein determination by high-performance gel-permeation chromatography.

A general high-performance gel-permeation chromatography (HPGPC) method was developed to determine protein in human serum with improved sensitivity and speed. The optimum UV wavelength for protein detection was found to be 210 nm, by comparing the protein values obtained by varying the UV wavelength of the HPLC detection system with the protein values obtained from spectrophotometric protein assays, i.e., the bicinchoninic acid (BCA) method and the biuret method. The analysis time was less than 1 min. Since this HPGPC serum protein assay method is simple and rapid, it is expected to be particularly well adapted for use in clinical laboratories.

Adolescent↗
PubMed1997

Mutants of the phytopathogenic fungus magnaporthe grisea deficient in alternative, cyanide-resistant, respiration

The phytopathogenic fungus Magnaporthe grisea has a cyanide-resistant respiratory pathway. The fungicide SSF-126 ((E)-2-methoxyimino-N-methyl-2-(2-phenoxyphenyl) acetamide) blocks the cytochrome electron transport of M. grisea and induces the alternative respiratory pathway. Twelve mutants of M. grisea more susceptible to SSF-126 than wild type were identified after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. Five mutants retained a reduced alternative respiration activity, and seven mutants lacked alternative pathway activity. A monoclonal antibody against the maize alternative oxidase cross-reacted against a 40-kDa mitochondrial protein of M. grisea, indicating that the 40-kDa protein is an alternative oxidase. Immunoblot analysis indicated that the seven completely deficient mutants grouped into two classes: four mutants produced the 40-kDa proteins while the other three mutants failed to produce the functional protein. Copyright 1997 Academic Press. Copyright 1997 Academic Press

Journal Article↗
PubMed1997

Primary familial polycythaemia associated with a novel point mutation in the erythropoietin receptor.

Primary familial and congenital polycythaemia (PFCP) is a rare disease characterized by congenital erythrocytosis inherited in an autosomal dominant fashion. Recently, mutations in the erythropoietin receptor (EpoR) have been identified in PFCP families. We describe a Japanese family with an autosomal dominant inheritance of PFCP. An in vitro colony assay demonstrated hypersensitivity of erythroid progenitors to erythropoietin (Epo) in affected family members. Sequence analysis of RT-PCR products amplified from the C-terminal region of EpoR transcripts in affected family members revealed that they were all heterozygous for C and T bases at position 5986, which suggested a genetic mutation (C to T) on one allele of EpoR. This mutation gave rise to a translation termination codon TAG at amino acid 435. Thus, the resulting EpoR is a truncated protein product lacking all 74 amino acids downstream of the mutation. To date, all genetic mutations affecting a family with PFCP, including this one, have been located in the cytoplasmic negative regulatory region of the EpoR. All mutations gave rise to truncated Epo receptors between Tyrosine 427 and Tyrosine 455. The phosphotyrosines in this region of EpoR have been demonstrated to be binding sites for SHP-1 phosphatase. Therefore PFCP is presumably brought about as a result of genetic mutations which cause the loss of the SHP-1 binding site in the cytoplasmic region of EpoR.

Base Sequence↗
PubMed1997

Optimal configuration of pyrene excimer induced by the excimer-forming two-probe nucleic acid hybridization method.

Excimer-forming two-probe nucleic acid hybridization (ETPH) method with pyrene as a fluorophore enables homogeneous hybridization assays. We examined the effect of linker length between a pyrene residue and a terminal sugar moiety on Tm of hybrids in the presence of 20% dimethylformamide (DMF). The results including those of CD measurements indicated no interaction of pyrene residues with the duplex formed between a target 32-mer and a pyrenemethyliodoacetamide-introduced 16-mer probe (PMIA-P5)/a pyrenebutanoic acid-introduced 16-mer probe (PBuA-P3), which is the best pair of probes for intense excimer emission. This was also supported by a computer-assisted molecular modeling using Insight II and Discover software.

DNA↗