Biomedical subjects

N Fujii

Publications and source records attributed to N Fujii.

At least 217 records · Page 12Linked to original sources

PubMed1997

Exercise-induced changes in beta-adrenergic-receptor mRNA level measured by competitive RT-PCR.

Competitive reverse transcription-polymerase chain reaction (RT-PCR) analysis was used to clarify whether dynamic exercise-induced increases in beta-adrenergic-receptor (beta-AR) number in human lymphocytes are accompanied by increases in the beta-AR mRNA level. Sixteen healthy subjects performed cycle ergometry until exhaustion. Before and immediately after exercise, peripheral blood was drawn from a forearm vein for preparation of lymphocytes. Both the beta-AR mRNA level and the beta-AR number were significantly increased by exercise. The changes in beta-AR mRNA level and beta-AR number were significantly correlated (r = 0.63, P < 0.01). This finding suggests that a rapid increase in beta-AR mRNA level might be an early adaptive response of the sympathetic nervous system to dynamic exercise. In vitro incubation of lymphocytes with epinephrine had no effect on beta-AR mRNA levels, nor did adenosine 3',5'-cyclic monophosphate, protein kinase C, or intracellular Ca2+ increase the beta-AR mRNA level in vitro. Therefore, it appears that other mechanisms underlie the exercise-induced elevation of beta-AR mRNA levels in human lymphocytes.

Adult↗

PubMed1997

Effect of 15-hydroperoxyeicosatetraenoic acid on the fibrinolytic factor release and the antithrombin binding of vascular endothelial cells.

15-Hydroperoxyeicosatetraenoic acid (15-HPETE), an arachidonate lipoxygenase product, is reported to induce severe endothelial injury. In this study, we examined the effect of 15-HPETE on the release of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) from cultured human umbilical vein endothelial cells (HUVEC). The addition of 15-HPETE to the serum-free medium reduced the release of t-PA antigen from HUVEC, while the release of PAI-1 antigen was significantly enhanced. However, treatment of the cultured HUVEC with alpha-tocopherol or nordihydroguaiaretic acid completely suppressed the 15-HPETE-induced change in t-PA and PAI-1 antigen release. 15-Hydroxyeicosatetraenoic acid (15-HETE) had no effect on the release of either antigen from cultured HUVEC. The HUVEC surfaces exposed to 15-HPETE decreased the potency for binding antithrombin III. In a reconstituted system with heparin and phosphatidylcholine, 15-HPETE decreased the ability of heparin to inactivate thrombin activity. These results suggest that the fibrinolytic factor release and the antithrombin binding of vascular endothelial cells are impaired by the attack of 15-HPETE, and that the presence of antioxidants prevents the injurious action of lipid hydroperoxide.

Antioxidants↗

PubMed1997

UCE6, a new antitumor antibiotic with topoisomerase I-mediated DNA cleavage activity produced by actinomycetes: producing organism, fermentation, isolation and biological activity.

A novel antitumor antibiotic, UCE6 (1,3,8,10,11-pentahydroxy-2-methyl-10-(2-oxo-4-hydroxypentyl)na phthacene-5, 12-dione) with topoisomerase I-mediated DNA cleavage activity, was isolated from the culture broth of actinomycetes strain UOE6. Addition of silicone oil antifoam agent, KS69 (2%), to the fermentation enhanced the production of UCE6 by approximately 3 fold. A total of 1.15 g of UCE6 was recovered as reddish orange crystals from a 100 liter fermentation supplemented with 2% KS69. UCE6 exhibited growth inhibitory activity against HeLa S3, HCT116 and Lu-65 cells comparable to that of camptothecin.

Actinomyces↗

PubMed1997

Isolation of genes involved in gravitropism.

When upright growing wild type barley seedling are placed to a horizontal position they will respond to this gravistimulation by a curvature against the gravitational force. The mutant serpentina, however, shows gravitropic response only in an early stage of development. Older seedlings, gravistimulated 92 h after germination are agravitropic. They will grow horizontally. We try to identify genes involved in gravitropism by comparing gene expression of i) non-gravistimulated and gravistimulated wild type barley seedlings and of ii) gravistimulated wild type and serpentina.

DNA Probes↗

PubMed1997

[A case of successful operation of tetralogy of Fallot in a 55-year-old man].

A 65-year-old man with Tetralogy of Fallot having respiratory dysfunction is reported. He had a history of pulmonary tuberculosis and experienced right upper lobectomy and thoracoplasty, he had severe hypoxemia (PaO2 35.0 mmHg, Sat, 68.5% under room air) and low quality of life. Total corrective surgery (patch closure for ventricular septal defect, patch enlargement for right ventricular outflow tract, pulmonary valve replacement with bioprosthesis) was performed. Pulmonary edema which was similar to adult respiratory distress syndrome occurred on the first postoperative day after temporary weaning from respirator although circulatory correction was successful. Management with respirator was continued until the 7th postoperative day. It seemed that high pulmonary blood flow and pulmonary hypertension after operation resulted in increase of capillary permeability of lung. One month later there was no gait disturbance and no dyspnea (PaO2 59.8 mmHg, Sat. 92.3% under room air). This patient was the oldest one with Tetralogy of Fallot undergoing successful corrective surgery.

Aged↗

PubMed1997

Reactivity of recombinant Treponema pallidum (r-Tp) antigens with anti-Tp antibodies in human syphilitic sera evaluated by ELISA.

We evaluated the immunoreactivity of recombinant Treponema pallidum (r-Tp) antigens with human sera by indirect enzyme-linked immunoabsorbant assay (ELISA). We expressed antigens with a molecular weight (MW) of 17KDa, 15KDa, 47KDa, and 42KDa, which are believed to be major immunoreactive membrane proteins of Tp cells. The expressed proteins were described by adding the prefix M, S, and G to the corresponding Tp antigens, namely, mature antigens, signal sequence containing antigens, and glutathione s-transferase (GST)-fused antigen in this report. A rather high expression occurred for M47 and S42 proteins in the Escherichia coli system, whereas for M15 and M17 proteins, a poor expression was observed. However, a fairly high expression occurred for G15 and G17. Thus expressed proteins were purified by means of chromatographies to a level of > 95%, and the purified proteins were found to be reactive with TPHA positive serum by Western blotting (WB). An ELISA performed with a serum of 1/1000 dilution using these purified antigens for coating on the solid phase showed that G17 antigen was more effective in detecting syphilis antibodies in human serum than M47, S42, and G15. There was a good consistency between ELISA and TPHA, whereby the cutoff indexes (CI) on ELISA showed a correlation coefficient of 0.7276 in logarithmic TPHA titers.

Animals↗

PubMed1997

Effects of football training on ventilatory and gas exchange kinetics to sinusoidal work load.

The purpose of this study was to evaluate the effects of football training on maximal oxygen uptake (VO2max), ventilatory threshold (VT) and kinetics of ventilation and gas exchange variables to sinusoidal work load. The sinusoidal work load during cycling exercise was varied from 30 watts to 60% of VO2max (60% VO2max) with a period of 2 min. O2 uptake (VO2), CO2 output (VCO2), minute ventilation (VE) and heart rate (HR) were measured on a breath-by-breath basis using a computer system. Training periods were continued for 9 months. Six males who had no football experience were performed in which VO2max, VT, and the kinetics of each variable were measured for 3-month intervals (PRE, TR.3, TR.6, and TR.9). They usually underwent football training, such as sprint and strength training for 2-3 hours day-1, 6 days week-1. Mean VO2max was significantly increased at TR.3 and TR.6. VT was also significantly increased during the training period. The amplitude of VO2, VCO2, VE, and HR responses during sinusoidal exercise unchanged during the training period. Phase shifts to work load in VO2 and HR responses did not significantly change during the 9 months, but the phase shift in VCO2 and VE responses significantly continued increasing as the training intervals progressed. These results suggest that football training does not significantly affect the development of the kinetics of VO2 and HR during submaximal exercise, but that it dramatically increases VO2max and VT values.

Anaerobic Threshold↗

PubMed1996

An anti-HIV peptide, T22, forms a highly active complex with Zn(II).

T22 ([Tyr5,12, Lys7]-polyphemusin II) has been shown to have strong anti-human immunodeficiency virus (HIV) activity, comparable to that of 3'-azide-2', 3'-dideoxythymidine (AZT). T22 takes an antiparallel beta-sheet structure maintained by two disulfide bridges and contains two antiparallel repeats of Cys-Tyr-Arg-Lys-Cys. As reported herein, fully reduced T22 was found by HPLC and ion spray mass spectrometric analyses to form a complex in a molar ratio of 1:1 with Zn(II) ion at neutral pH in aqueous solution. Complexation of Zn(II) ion to this peptide appears to result in tetracoordinate bonding to sulfur atoms of four Cys residues. We also found that the anti-HIV activity of the T22-Zn(II) complex was fourfold stronger than that of T22.

Amino Acid Sequence↗

PubMed1996

Analysis of the interaction of an anti-HIV peptide, T22 ([Tyr5, 12, Lys7]-polyphemusin II), with gp120 and CD4 by surface plasmon resonance.

We have previously found that T22 ([Tyr5, 12, Lys7]-polyphemusin II) exhibits strong anti-human immunodeficiency virus (HIV) activity comparable to that of 3'-azido-2', 3'-dideoxythymidine (AZT). The inhibition mechanism of T22 on HIV-replication has not been elucidated precisely yet, and hence the target molecules of T22 have not been identified. However, our recent research suggested that T22 exerts its effect by blocking virus-cell fusion at an early stage of HIV infection and that T22 might interact with an HIV envelope protein and/or a T-cell surface protein, both of which are critical for HIV infection. In this paper we demonstrated that T22 binds specifically to both gp120 (an envelope protein of HIV) and CD4 (a T-cell surface protein) and that both bindings can be inhibited by an anti-T22 antibody, using biosensor technology (BIAcoreTM) based on the principles of surface plasmon resonance. Linearization by the BIAcoreTM system (BIAlogue software) and nonlinear least squares analysis by curve fitting with exponential equations showed that both interactions have close dissociation constants (approximately 10(-7) M). The present study suggests that T22 inhibits the virus-cell fusion process through binding to both gp120 and CD4.

Amino Acid Sequence↗

PubMed1996

Light-sensitive response in melanophores of Xenopus laevis: II.Rho is involved in light-induced melanin aggregation.

Melanophores of the isolated tail fin of the Xenopus tadpole aggregate melanin granules in response to light. This aggregation was found to be inhibited by subcutaneous injection of exoenzyme C3 of Clostridium botulinum. A 26 kDa protein in homogenate obtained from the Xenopus tail fin was ADP-ribosylated by exoenzyme C3. This reaction was inhibited effectively by a monoclonal antibody, anti-Rho mab A5. raised against the small GTP-binding protein Rho. The extent of ADP-ribosylation depended on light and guanine nucleotide. Incubation under illumination partly reduced ADP-ribosylation and the reduction was restored by addition of guanine nucleotide during incubation. These findings suggest that Rho is involved in the photo-sensitive melanophore response as a signal transducer linking photo-stimuli to melanin granule translocation with Xenopus melanophores.

ADP Ribose Transferases↗

PubMed1996

An antimicrobial peptide, magainin 2, induced rapid flip-flop of phospholipids coupled with pore formation and peptide translocation.

The effect of an antimicrobial peptide, magainin 2, on the flip-flop rates of phospholipids was investigated by use of fluorescent lipids, i.e., anionic N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)dipalmitoyl-L-alpha- phosphatidylethanolamine (NBD-PE), 1-oleoyl-2-[12-((7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)- dodecanoyl]-L-alpha-phosphatidic acid (C12-NBD-PA), 1-oleoyl-2-[12- ((7-nitrobenz-2-oxa-1,3-diazol-4-yl)- amino)dodecanoyl]-L-alpha-phosphatidyl-L-serine (C12-NBD-PS), and zwitterionic 1-palmitoyl-2-[6-((7- nitrobenz-2-oxa-1,3-diazol-4-yl)amino)caproyl]-L-alpha-phosphatidy lcholine (C6-NBD-PC). Their intrinsic flip-flop half-lives at 30 degrees C in the absence of the peptide were 1.1 h, ca. 7 h, ca. 8 days, and > 2 days, respectively. The peptide accelerated the flip-flop half-lives of the fluorescent lipids to an order of minutes. Furthermore, the flip-flop was coupled with the membrane permeabilization and the peptide translocation [Matsuzaki, K., Murase, O., Fujii, N., & Miyajima, K. (1995) Biochemistry 34, 6521-6526], suggesting pore-mediated flip-flop. The flip-flop rate was independent of the initial labeling conditions (outer leaflet label or inner leaflet label). From these results, a model was proposed, in which the lipids translocate across the membrane by lateral diffusion along the wall of the pores composed of the peptides and the lipids. A simple theoretical calculation could explain the coupling of the flip-flop with the permeabilization.

Amino Acid Sequence↗

PubMed1996

Mosaic type of the nontoxic-nonhemaggulutinin component gene in Clostridium botulinum type A strain isolated from infant botulism in Japan.

The gene encoding the nontoxic-nonhemaggulutinin (NTNH) component was amplified by the PCR technique using two primer sets and the DNA template from Clostridium botulinum type A strain 7I03-H isolated from infant botulism in Japan. The nucleotide sequence revealed that the NTNH gene was composed of 1,193 amino acids with a molecular weight of 130868.08. Furthermore, the N-terminal half side and C-terminal half side of the NTNH component were similar to the NTNH component of type C and type A, respectively. These results indicate that the NTNH component gene codes the mosaic NTNH component composed of type A and type C. The hemaggulutinin gene, aha, and ORF-22 gene, orf-22a, were undetectable in the region upstream of the NTNH component gene, ant. Therefore, orf-22a is not thought to play a key role in the expression of botulinum type A progenitor toxin gene.

Amino Acid Sequence↗

PubMed1996

Mosaic structures of neurotoxins produced from Clostridium botulinum types C and D organisms.

We isolated the gene encoding a botulinum neurotoxin (BoNT) of 1285 amino acids with a molecular weight of 147,364 from the toxigenic bacteriophage d-sA of Clostridium botulinum type D strain South African (Dsa). The BoNT of Dsa (BoNT/Dsa) is composed of three regions on the basis of the homology to BoNT types C1 (BoNT/C1) and D (BoNT/D). The N-terminal (Met-1 to Val-522) and the C-terminal regions (Trp-945 to Glu-1285) have high identity to corresponding regions of BoNT/D (96% identity) and BoNT/C1 (74% identity), respectively. The core region (Pro-523 to Lys-944) is common to three toxins (83% to 92% identity). These results suggest that neurotoxins produced from Clostridium botulinum types C and D are composed in a mosaic-like fashion.

Amino Acid Sequence↗

PubMed1996

Phorbol 12-myristate 13-acetate stimulates the release of glycosaminoglycans from cultured vascular endothelial cells: possible involvement of protein kinase C activation.

We investigated the release of glycosaminoglycans (GAGs) labeled with [3H]glucosamine and [35S]sulfate into the medium from cultured bovine aortic endothelial cells stimulated by phorbol 12-myristate 13-acetate (PMA) which is an activator of protein kinase C (PKC). The GAG release was significantly accelerated by PMA without an increase in the leakage of lactate dehydrogenase but was unchanged by 4 alpha-phorbol 12,13-didecanoate which lacks the ability of PKC activation. The acceleration of GAG release by PMA was strongly suppressed by a PKC inhibitor H-7 but not by HA 1004 which is an inactive analogue of H-7. Characterization of GAGs released into the medium revealed that PMA increased both heparan sulfate and the other GAGs in a similar degree. Although the release of GAGs stimulated by thrombin was also suppressed by another PKC inhibitor staurosporine, stimulation by plasmin was unaffected by the inhibitor. The present data suggest that protein kinase C mediates the release of endothelial cell GAGs including anticoagulant heparan sulfate and the stimulation of the release by thrombin includes this mechanism.

Animals↗

PubMed1996

Characterization of component-I gene of botulinum C2 toxin and PCR detection of its gene in clostridial species.

Botulinum C2 toxin is composed of two nonlinked protein components, component-I (light chain) and component-II (heavy chain). It is produced by Clostridium botulinum types C and D, and is thought to play a lethal pathogenic role. These biological activities of C2 toxin may be due to the ADP-ribosylation of non-muscle actin by component-I of the toxin. We were able to isolate two overlapping gene fragments encoding component-I from the chromosomal DNA of Clostridium botulinum type C strain (C)-203U28, and determine the complete nucleotide sequence of component-I gene. The gene for component-I, bc21, consists of one open reading frame (ORF) encoding 431 amino acid residues (1293 nucleotides) without signaling peptide sequence. The molecular mass calculated from the deduced amino acid sequence was 49400.37 Da. Mono-ADP-ribosyltransferase activity was demonstrated in the lysate from E. coli transformed by the recombinant plasmid, pGEM-C2 encompassing whole component-I gene with its own promoter.

Amino Acid Sequence↗

PubMed1996

Interaction of an anti-HIV peptide, T22, with gp120 and CD4.

T22 ([Tyr5,12, Lys7]-polyphemusin II) has been shown to have strong anti-human immunodeficiency virus (HIV) activity. The precise mechanism of action of T22 on HIV-replication has not been elucidated yet, nor have the targets of T22 been identified. However, our previous research suggested that T22 exerts its effect by blocking virus-cell fusion and that T22 might interact with an HIV envelope protein and/or a T-cell surface protein. Herein we use a novel biosensor based on the principles of surface plasmon resonance (BIAcore) to demonstrate that T22 binds specifically to both gp120 (an envelope protein of HIV) and CD4 (a T-cell surface protein) and that both bindings can be inhibited by an anti-T22 antibody. The data obtained suggest that T22 inhibits virus-cell fusion through the double binding to the above two proteins.

Amino Acid Sequence↗

PubMed1996

Quantitative detection of secretory immunoglobulin A to Helicobacter pylori in gastric juice: antibody capture enzyme-linked immunosorbent assay.

Helicobacter pylori is a major etiologic agent in gastroduodenal disorders. In this study, immunoglobulin A (IgA) antibodies to H. pylori were estimated in serum and gastric juice specimens from patients with gastritis and peptic ulcers using antibody capture enzyme-linked immunosorbent assays (ACELISAs). The antibody titers of the ACELISAs are independent of the antibody concentration and reflect the ratio of H. pylori-specific IgA to total IgA. The ratio is stable, although the antibody concentration fluctuates in gastric juice. Using the ACELISAs it was possible to evaluate quantitatively not only serum IgA (SR-IgA) antibodies but also secretory IgA (SC-IgA) antibodies in gastric juice. There were significant differences between the patients and control group in the SR-IgA and SC-IgA ACELISAs. Furthermore, the ACELISAs made it possible to compare between SR-IgA antibodies in serum and SC-IgA antibodies in gastric juice. In all patients, the ratios of H. pylori-specific IgA were higher in gastric juice than in serum. These results suggest that H. pylori SC-IgA antibodies are mainly produced by the local immune response in the gastric mucosa. Our studies indicate that ACELISA is well suited for the analysis of local immune response in mucosa.

Adult↗

PubMed1996

Cytokines in the serum and brain in mice infected with distinct species of Lyme disease Borrelia.

This study describes the detection of cytokines, interleukin-1 alpha (IL-1 alpha), tumor necrosis-factor alpha (TNF alpha) and interleukin-6 (IL-6) in the serum and brain homogenates of susceptible and resistant strains of mice infected with distinct species/strains of Borrelia. Significant elevation of inflammatory cytokines was found in the sera of susceptible C3H/ HeN mice but not in the sera of resistant BALB/c mice on days 7 and 45 after inoculation. Brain cytokines were observed in C3H/HeN mice infected with B. garinii and B. afzelii and the production was associated with the presence of spirochetes. B. japonica was the only exception in disease-susceptibility and cytokine production of mice. These results suggest that there are differences in pathogenic potential amongst Borrelia strains, and that the susceptible mice demonstrate a stronger cytokine response and greater frequency of recovery of Borrelia from the brain than do the resistant mice.

Animals↗