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T Takagi

Publications and source records attributed to T Takagi.

At least 379 records · Page 21Linked to original sources
PubMed1995

Thermodynamic and molecular properties of the interaction between amphioxus calcium vector protein and its 26 kDa target.

Calcium vector protein (CaVP) of amphioxus shares some common structural features with Ca(2+)-dependent activators such as troponin C and calmodulin, and is associated in vivo with a 26 kDa (CaVPT), a multidomain protein with one IQ- and two IgII-motifs. Isolated CaVP binds two Ca2+ ions with very different intrinsic affinity constants: K'Ca1 = 4.9 x 10(6) M-1 and K'Ca2 = 7.3 x 10(3) M-1, respectively. In the complex with CaVPT, CaVP also binds two Ca2+, but with strong positive cooperativity (nH = 1.9) and with distinctly higher affinity: K'Ca1 = 2.4 x 10(5) M-1 and K'Ca2 = 1.0 x 10(8) M-1. Since neither in the isolated CaVP nor in the complex Ca2+ binding is influenced by 2 mM MgCl2, both sites can be considered as Ca(2+)-specific. In the absence of Ca2+, the complex is stable under physiological conditions, but the interaction is governed by the principle of linked functions and Ca2+ binding to CaVP reinforces the affinity between CaVP and CaVPT 70-fold. Both proteins interact with the hydrophobic probe 2 p-toluidinylnaphthalene-6-sulfonate (TNS), but CaVPT enhances the fluorescence 45-fold, CaVP-Ca2 and metal-free CaVP only 10- and 5-fold, respectively. Complex formation between CaVPT and CaVP leads to a 3-fold reduction of the fluorescence enhancement, suggesting that a strong solvent-shielded hydrophobic core is formed. CaVP contains two highly reactional thiols (kSH > 0.3 s-1) for 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB); CaVPT contains three thiols, two of them also with kSH > 0.3 s-1 in the native state.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1995

A new mode of size-dependent separation of proteins by capillary electrophoresis in presence of sodium dodecyl sulfate and concentrated oligomeric dextran.

Capillary electrophoresis in presence of sodium dodecyl sulfate (SDS) and 10% w/v of oligomeric dextran with molecular weight of just above 1000 was found to be an efficient medium for size-dependent separation of proteins (Karim, M. R., Janson, J.-C., Takagi, T., Electrophoresis 1994, 15, 1531-1534). The separations were found to be highly reproducible, both with respect to the position and relative amounts of the peaks. No evidence for a network structure in the medium could be found on examination of the effect of dextran concentration and viscosity measurements. The separation mechanism appears to be different from sieving by a polymer network structure. In free solution, SDS-protein complexes with molecular weights > 10,000 migrate with almost the same mobilities, irrespective of their molecular weight (this behavior is called free draining). Such SDS-complexes of proteins or peptides with molecular weights < 10,000, however, tend to increase their negatively signed mobilities with decreasing molecular weight (Karim, M. R., Shinagawa, S., Takagi, T., Electrophoresis 1994, 15, 1141-1146). Our working hypothesis is that in presence of the oligomeric dextran, the range of deviation from the free-draining electrophoretic behavior extends to higher molecular weights, resulting in a novel separation made.

Circular Dichroism↗
PubMed1995

Role of the perforating vein in vascular pedicle of free forearm flap.

An innovation in the preparation of the vascular pedicle of the free radial forearm flap is presented. While the radial artery is commonly used as the arterial pedicle of the flap, either the cutaneous venous system or the radial comitant vein (deep venous system) is used as the venous pedicle. The perforating vein communicates between these two venous systems at the cubital fossa, and we confirmed its presence in all but one of more than 180 cases. When the vascular pedicle is dissected proximally to the perforating vein contained in the flap, the venous drainage of both the deep and cutaneous systems can be restored by anastomosis of only one vein: the cutaneous or the radial comitant vein. On the other hand, the flap can be raised with the radial vessels (without the cutaneous vein) at the start of surgery, and a large caliber cutaneous vein, such as the median cubital, the cephalic, or the basilic, can be used for anastomosis in cases where the cutaneous veins in the distal forearm are too thin, or where the radial comitant vein is composed of two thin separated veins. We believe that preserving the perforating vein would make the forearm flap more reliable and more convenient in reconstructive surgery.

Forearm↗
PubMed1995

Detection of antibodies to 65 KD heat shock protein and to human superoxide dismutase in autoimmune hepatitis-molecular mimicry between 65 KD heat shock protein and superoxide dismutase.

The antibody to 65 KD mycobacterial heat shock protein (HSP65) and antibody to human superoxide dismutase (H-SOD) were measured by ELISA in patients with autoimmune hepatitis (AIH), and results were compared with those of patients with chronic active hepatitis C (CAH-C) or systemic lupus erythematosus (SLE) and normal subjects (NS). Patients with AIH had significantly higher OD values of anti-HSP65 antibody and anti-H-SOD antibody compared with those of patients with CAH-C or SLE and NS. OD values of anti-HSP65 antibody were correlated with those of anti-SOD antibody. Affinity-purified anti-SOD antibody reacted with HSP65. Analysis of the amino acid sequence of human SOD showed that 7 segments, corresponding to r to 25 amino acid residues, exhibited 50 to 71% homology with that of my mycobacterial HSP65.

Amino Acid Sequence↗
PubMed1995

Primary sclerosing cholangitis with marked eosinophilic infiltration in the liver.

A 16-year-old boy was diagnosed as having primary sclerosing cholangitis (PSC), based on retrograde cholangiography showing mixed features of narrowing and dilatation of the common hepatic and intrahepatic bile ducts. However, periductal fibrosis was not observed in the needle biopsy liver specimen. The liver biopsy specimen obtained 11 years previously, at the onset of the disease had disclosed a marked infiltration of eosinophils in the portal tract with eosinophilic catinonic protein immunostaining, with marked eosinophilia (54%) being noted. In Japanese reports, eosinophilia of more than 7% was reported in 13 of 32 (40.6%) PSC patients. However, the early stage of PSC, with marked eosinophilia and eosinophilic infiltration in the liver, such as in the present case, has rarely been reported. The findings in this case suggest that eosinocytes are related to the pathogenesis of PSC.

Adolescent↗
PubMed1995

Assessment of micronucleus induction in SCCVII cells treated with bioreductive agents, WIN 59075 (SR 4233) and mitomycin C, under aerobic and hypoxic conditions.

WIN 59075 (SR4233, tirapazamine) is a promising bioreductive antitumor agent preferentially more toxic to hypoxic cells and presently undergoing phase I clinical trials. In this investigation, we have examined the applicability of the cytokinesis-block micronucleus assay to assess the effects of bioreductive agents. SCCVII tumor cells were treated with WIN 59075 or mitomycin C at various concentrations under aerobic and hypoxic conditions. Significant induction of micronuclei in binucleate cells was demonstrated in a dose-dependent fashion and it appeared to be strongly correlated with the loss of clonogenicity in the colony assay. Both agents showed selectively higher toxicity to hypoxic cells than to aerobic cells and the ratios of the concentrations required to obtain the equivalent effects under aerobic and hypoxic conditions could be also estimated by this method as follows: the hypoxic toxicity ratios were 120-130 for WIN 59075 and 3.0-3.3 for mitomycin C. For several favorable characteristics, the cytokinesis-block micronucleus assay can provide an alternative, rapid, and reproducible means for evaluation of antitumor activities from chromosomal breakage caused by the bioreductive agents.

Dose-Response Relationship, Drug↗
PubMed1995

Cloning of a retinoic acid-induced gene, GT1, in the embryonal carcinoma cell line P19: neuron-specific expression in the mouse brain.

Mouse P19 embryonal carcinoma cells can be reproducibly differentiated into neurons and glial cells upon treatment with high concentrations of retinoic acid (RA). To understand the molecular mechanisms that control early neural differentiation, we constructed P19 cell lines carrying an insertion of a gene-trap vector containing lacZ as the reporter gene and a G418 resistance gene. We tested expression of the lacZ gene during the RA-induced differentiation process of 300 clones selected with G418. Ten of these clones were stained with X-gal, and five of these ten clones showed up- or down-regulation of lacZ expression. We analyzed one clone, GT1, in which expression of the lacZ gene was markedly up-regulated. The 5'-flanking genomic DNA of the GT1 gene present at the site of integration was isolated by the plasmid rescue method, and we screened a cDNA library using this DNA gene as a probe. The GT1 cDNA is about 9000 bp long, with an open reading frame encoding 1840 amino acids. This amino acid sequence has a potential glycosaminoglycan attachment site (Ser-Gly-Gly-Gly) and three N-linked glycosylation sites, but no signal peptide. The sequence of GT1 does not show significant homology with any other known proteins, suggesting that GT1 may be a novel proteoglycan core protein. In situ hybridization revealed that GT1 mRNA was expressed ubiquitiously in the adult mouse brain. This expression was specifically localized in neurons but not in glial cells. Immunohistochemistry revealed that GT1 protein was also localized in neurons. These results suggest that this protein may play a fundamental role in neurons.

Amino Acid Sequence↗
PubMed1995

GAP-43 mRNA suppression by the ribozyme in PC12 cells and inhibition of evoked dopamine release.

We constructed a ribozyme designed to cleave the GAP-43 mRNA and which contained a bacteriophage T7 transcription terminator at its 3' site to maintain stability. The ribozyme was overexpressed in PC12 cells by pEF-BOS, a powerful mammalian expression vector. Consequently, PC12 cells overexpressing the GAP-43 ribozyme revealed a drastic decrease in the levels of GAP-43 mRNA expression, and the evoked dopamine release was significantly suppressed in these cell lines. These results support the previous observations that GAP-43 is associated with Ca-dependent dopamine release in PC12 cells, and the ribozyme expression system used in the present study was demonstrated to be useful for suppression of the functions of specific mRNAs and exploration of specific gene products.

Animals↗
PubMed1995

Analysis of cyclic feed intake in rats fed on a zinc-deficient diet and the level of dihydropyrimidinase (EC 3.5.2.2).

The body weight and feed intake of rats fed on a Zn-deficient diet for 28 d were reduced compared with those of control rats. The feed intakes of the Zn-deficient and control groups during the period were 10.2 (SE 0.3) and 15.7 (SE 0.2) g/d respectively. Cyclic variations in feed intake and body-weight changes were found in analysis not only of all the data for five rats but also that in each individual rat. Cosinor analysis revealed that the cyclical period of both the feed intake and body-weight change in the Zn-deficient rats was 3.5 (SE 0.1) d. The mesor and amplitude value of the feed intake in the Zn-deficient rats was 10.1 (SE 0.4) g/d and 3.5 (SE 0.5) g/d respectively, and that of body-weight change was 1.4 (SE 0.1) g/d and 7.9 (SE 1.3) g/d respectively. Among pyrimidine-catabolizing enzymes, dihydropyrimidinase (EC 3.5.2.2) activity showed significant retardation in the Zn-deficient rat liver with decrease of the enzyme protein. The ratio of apo-form to holo-form dihydropyrimidinase in the liver was not affected by the Zn-deficient diet.

Amidohydrolases↗
PubMed1995

Maintaining low concentrations of plasma beta 2-microglobulin through continuous slow haemofiltration.

As a first step in the development of a future wearable artificial kidney, we conducted three forms of treatment with continuous haemofiltration (CHF) on a group of 10 patients in an attempt to determine what plasma values of small molecules and beta 2-microglobulin (beta 2-M) could be maintained. In the first system, one ordinary 4-h haemodialysis, followed by 7-day CHF with 51 exchange per day, was repeated. The second system consisted of CHF with 51 exchange/day and thrice weekly slow nocturnal dialysis. The third system used CHF with 101 exchange per day. The first, second and third systems were used with three, four and four patients, respectively, for at least 4 weeks each. PAN-DX and FH-66 haemofilters were used eight and three times, respectively, with continuous infusion of heparin at 500-700 units/h. In the first system, the pre-CHF plasma beta 2-M was 45.5 +/- 3.1 mg/l, against a much lower 18.8 +/- 1.0 mg/l 4 weeks later. With the second system, this decrease was from 43.5 +/- 5.7 mg/l to 18.1 +/- 1.1 mg/l with 4 weeks treatment, and from 44.7 +/- 3.4 mg/l to 18.1 +/- 1.4 mg/l with 3 weeks treatment. Pre-haemodialysis treatment levels of urea nitrogen, plasma creatinine and uric acid in the first system were greater than ordinary pre-haemodialysis levels. On the second system, these were kept at -54 +/- 8.3%, -52.2 +/- 6.7% and -47.6 +/- 4.4% of the ordinary pre-haemodialysis levels, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Protein factors required for in vitro transcription of Sendai virus genome.

To elucidate the mechanism of transcription and replication of Sendai virus, we developed an efficient and faithful in vitro transcription system using purified virus particles. The in vitro RNA synthesis was almost entirely dependent on the addition of eukaryotic cell extracts, including those from various cultured mammalian cells, mammalian tissues, and even from plant cells. The RNA products were almost identical to authentic mRNA species synthesized in the infected cells, in their size distribution, the presence of 3'-poly(A) tail and the presence of methylated 5'-cap structure (m7GpppAm). Ribonuclease protection experiments after annealing the in vitro RNA with viral genomic RNA (vRNA) indicated that the virion-associated RNA-dependent RNA polymerase transcribes correct regions of the RNA genome in vitro. The active component(s) that is required for Sendai virus mRNA synthesis was partially purified from bovine brain and was separated into at least two complementary fractions, one of which could be replaced by highly purified cellular tubulin. When viral ribonucleoprotein complexes were used instead of virus particles in the in vitro transcription, only Sendai virus-infected cell extracts supported mRNA synthesis, and extracts from uninfected cells or cells infected with other viruses were found to be inert. These results suggest that, in addition to the general factors which are present ubiquitously in eukaryotic cells, a factor(s) specific to Sendai virus-infection is required for Sendai virus transcription.

Animals↗
PubMed1995

In vitro mRNA synthesis by Sendai virus: isolation and characterization of the transcription initiation complex.

We have developed an in vitro transcription system using purified Sendai virus particles in which viral mRNA synthesis is almost entirely dependent on the addition of cellular proteins (host factors), one of which can be replaced by highly purified cellular tubulin [Mizumoto et al. (1995) J. Biochem. 117, 527-534]. In this study, to elucidate the function of host factors in transcription, we isolated an active initiation complex as a viral ribonucleoprotein, by incubating virus particles with bovine brain extract in the absence of nucleoside triphosphates, followed by ultracentrifugation. RNA products from the isolated initiation complex contained six mRNA species corresponding to all the virus-encoded genes, and most of them had a 5'-cap structure as well as a 3'-poly(A) tail. Immunoblotting showed that tubulin was specifically associated in the active complex. These data suggest that cellular tubulin, one of the host factors essential for Sendai virus transcription, interacts with the viral ribonucleoprotein to form an active complex at the initiation step.

Animals↗
PubMed1995

Peripherally biased distribution of antigen proteins on the recombinant yeast-derived human hepatitis B virus surface antigen vaccine particle: structural characteristics revealed by small-angle neutron scattering using the contrast variation method.

The internal structure of the recombinant yeast-derived human hepatitis B virus surface antigen vaccine particle was investigated by small-angle neutron scattering using the contrast variation method. Data were collected in aqueous buffer solutions containing 0, 40, 60, and 100% D2O in the q range of 0.005 to 0.2 A-1 at 5 degrees C. The radius of gyration at infinite contrast and the maximum dimension of the particle were estimated to be 107 and 290 A, respectively. The contrast matching point of the particle was determined to correspond to about 30% D2O, indicating that a considerable portion of the vaccine particle is made up of lipids and carbohydrates from yeast. The distance distribution function of the particle at 40% D2O, at which the protein components are matched out to show only the distribution of the remaining lipids and carbohydrates, differed markedly from the functions at other D2Os, and showed the nearly symmetrical profile characteristic of a spherical particle with a diameter of 240 A. The Stuhrmann plot and profile of the distance distribution function at 40% D2O showed that (i) the vaccine is a spherical particle with a diameter of 290 A, in which two different regions in terms of scattering density are distributed radially, (ii) the lipids and carbohydrates form a spherical cluster with a diameter of 240 A in the core region of the particle, and (iii) the surface antigen protein is present in the peripheral region. This architecture of the vaccine particle is favorable for the induction of anti-virus antibodies.

Cloning, Molecular↗
PubMed1995

T cell-rich B cell lymphoma bearing Epstein-Barr virus in tumor cells: a case of IBL-T-like lesion following Lennert's lesion.

A case of T cell-rich B cell lymphoma (TCRBCL) with Epstein-Barr virus (EBV) infection in tumor cells is reported. A 50 year old male developed right cervical lymph node swelling in July 1988. Initial biopsy in April 1989 demonstrated many scattered Hodgkinoid atypical cells with Lennert's lesion. After partial remission following chemotherapy, the lymph nodes enlarged again, and a second biopsy in February 1991 showed an IBL-T-like lesion. Only a small number of Hodgkinoid atypical cells were still observed. After apparently, complete remission, the lesion soon recurred and the patient died in November 1992. Immunohistochemically the Hodgkinoid cells were positive for L26, but negative for LN2, LN3, UCHL-1, MT1, lysozyme, Ber-H2 and Leu-M1. Reactivity for immunoglobulins showed false-positive because of polyclonal staining. IgH monoclonality was detected by the polymerase chain reaction method in the first biopsied specimen, and by Southern blotting in the second biopsied snap-frozen specimen. Monoclonal TCR beta rearrangement was not detected. The Hodgkinoid atypical cells were positive for EBV-encoding RNA by in situ hybridization, and LMP-1 by immunostaining. Occasionally, EBV-bearing immunoblastic, medium sized, or small lymphocytic cells were also observed. This case indicates the possibility that EBV is related to the pathogenesis of TCRBCL.

Blotting, Southern↗
PubMed1995

Cyanamide-associated alcoholic liver disease: a sequential histological evaluation.

This is the first study that we are aware of that followed the histopathological progression of the liver disease that was caused by the combination of both chronic alcohol use and cyanamide, an antidipsotropic agent. Two sequential liver biopsy specimens were obtained on 29 alcoholics who relapsed with varying histories of cyanamide treatment. Cyanamide induced ground-glass inclusions (GGIs) in the hepatocytes. Two groups were identified, depending on whether GGIs proliferated or regressed, which was, in turn, found contingent on the duration of cyanamide treatment and the drug-free period. Group 1 included 14 cases in which GGIs either emerged only in the second biopsy specimen or else were increased in the second specimen as compared in the initial specimen. Group 2 composed of 15 cases in which GGIs were either not observed in either specimen or decreased in the second specimen as compared in the initial specimen. Acidophilic bodies were sequentially increased in five cases (36%) of group 1 and in none of group 2. The severity of portal inflammation worsened in 10 cases (71%) of group 1 but in 2 cases (13%) of group 2, although the changes in fibrotic process did not differ between two groups. These differences could not be explained on the basis of the daily ethanol consumption and the length of relapses of the two groups. Thus, when cyanamide-treated alcoholics relapsed, the combined effect of cyanamide and alcohol produced the development of acidophilic bodies and portal inflammation along with the emergence of GGIs.

Adult↗
PubMed1995

Association of primary sclerosing cholangitis, thymoma and hypogammaglobulinemia.

A 64-year-old Japanese woman with thymoma has been suffering from diarrhea and increased alkaline phosphatase levels without jaundice. Her serum immunoglobulin levels of IgM and IgG were less than half of the normal levels, with an increase in CD8 (suppressor/cytotoxic) T cell percentage and a decrease in CD4 (helper) T cell percentage, resulting in a lower CD4/CD8 ratio of 0.31. These immunological features are in accordance with those of hypogammaglobulinemia complicating thymoma. Cholangiography and a liver biopsy specimen disclosed the presence of primary sclerosing cholangitis (PSC). PSC has been recognized in various immunodeficiency syndromes and this case shows that thymoma complicated by hypogammaglobulinemia is associated with PSC.

Agammaglobulinemia↗
PubMed1995

[Survey bacterial isolates from blood samples during 1987-1993 in our department].

We analyzed the changes in frequency of bacterial isolates from the blood samples in our department from May 1987 to December 1993. 565 isolates from 4887 samples (11.6%) were detected. Among the detected microorganisms, the rate of gram-positivecocci (GPC) was much higher than the other kinds of the isolates each year. Especially, 80-90% of GPC were occupied by only 2 kinds of microorganisms, coagulase negative Staphylococci (CNS) and S. aureus. Among gram-negative-rods (GNR), constant increase of S. marcescens and transient increase of Enterobacter and P. aeruginosa were recognized. In 30 cases (5.3%), 2-3 kinds of microorganisms were isolated concomitantly, and in 55 cases (9.7%), the microorganisms, which was mainly caused by CNS, S. aureus and Candida, was isolated from both blood samples and the tip of the IVH catheter concomitantly. 42.5% of the bacterial positive cases in 1933 underwent 2 more kinds of the indwelling catheters and 48.3% were administrated antibiotics. Most of the cases had underlying diseases including mainly malignant tumor (leukemia, solid tumor), cerebrovascular diseases, and multiple injuries.

Bacteremia↗