PubMed Health⌕ Search

Biomedical subjects

Y Tsujimoto

Publications and source records attributed to Y Tsujimoto.

At least 145 records · Page 8Linked to original sources
PubMed1994

Study on hypomineralized areas in hamster molars.

Hypomineralized area (HMA) scores were determined for hamster molars during tooth maturation and fluoride treatment. It was found that the molars were maturing until the animals were 45 days old, but from 45 to 74 days of age the HMA scores remained constant. Fluoride treatment decreased the HMA score. The group with the lowest HMA score was fed a cariogenic diet, inoculated with Streptococcus mutans and received topical fluoride treatment.

Animals↗
PubMed1994

Effect of smear layer removal agent and/or fluoride on the surface of dentin.

A study was conducted to observe the effectiveness of an EDTA-based agent, Tubulicid Red, and a polyacrylic acid-based agent, Dentin Conditioner, for removal of the smear layer from a prepared dentin surface, with or without a fluoride dentin reinforcing agent, using the dye penetration test and scanning electron microscopy (SEM). Bovine mandibular first and second incisors were used. After removal of the enamel, the smear layer on the dentin surface was treated with 38% H3PO4, Tubulicid Red, Dentin Conditioner, 1% NaF, 1% SnF2, Tubulicid Red (including 1% SnF2), Dentin Conditioner (including 1% NaF) and Dentin Conditioner (including 1% SnF2). In the dye penetration test, Dentin Conditioner (including 1% SnF2) was the most effective agent for preventing dye penetration. SEM evaluation of the dentin surface after treatment with the smear layer removal agents and/or fluorides showed that the smear layer was removed by H3PO4 and Dentin Conditioner. However, dentinal plugs remained after treatment with Dentin Conditioner alone. The other agents left some layers on the dentin surface.

Acid Etching, Dental↗
PubMed1994

[Molecular biology of cell death].

Apoptosis is an active mechanism for cell death that is characterized by unique biochemical processes, including nuclear condensation, cytoplasmic compaction and breaking up of the cells into a number of membrane-bound fragments called apoptotic bodies. Many physiological cell death is known to proceed by apoptosis, and importance of cell death in a variety of biological phenomena is now well recognized. Eukaryotic molecular biology resulted in the identification of several genes with an ability to modulate apoptosis. Some genes induce and the others inhibit apoptotic cell death. These include oncogenes (bcl-2, myc etc), anti-oncogenes (p53) and cell surface antigen genes (Fas, TNF receptor etc). Genetical approach to dissect programmed cell death, majority of which proceed by apoptosis resulted in the identification of several crucial genes involved in cell death processes (ced 3, ced 4, ced 9 etc. in C. elegans). In this chapter, I will overview genes involved in cell death, and show where we are now standing toward complete understanding of apoptosis in biochemical terms.

Apoptosis↗
PubMed1993

Effect of bcl-2 on Fas antigen-mediated cell death.

Fas Ag is a cell surface protein that can mediate apoptosis and belongs to the TNF receptor family. The product of protooncogene bcl-2, a membrane-associated protein, has been shown to inhibit apoptosis in various hematopoietic cells including B cells and T cells. To examine the possible interaction of the Fas Ag and bcl-2, we coexpressed human Fas Ag and bcl-2 cDNA in murine IL-3-dependent FDC-P1 cell line and murine lymphoma WR19L. FDC-P1 transformants expressing bcl-2 showed a prolonged survival to IL-3 depletion. FDC-P1 transformants expressing the Fas Ag alone were killed by anti-Fas antibody in the presence of IL-3. Overexpression of bcl-2 in FDC-P1 resulted in a partial inhibition of Fas-induced cell death. WR19L transformants expressing bcl-2 were partially resistant to the cytolytic activities of the TNF-alpha and anti-Fas antibody treatment. These results suggest that the Fas Ag and TNF receptor may share the same signaling pathway, and that bcl-2 interferes with the apoptotic process mediated by the Fas Ag and TNF receptor.

Antigens, Surface↗
PubMed1993

Long-range mapping of the 11q23 region involved in chromosome aberrations in human tumors by pulsed-field gel electrophoresis with a yeast artificial chromosome.

We have previously demonstrated that the RCK gene involved in t(11;14)(q23;q32) and the more centromeric MLL/ALL1 gene involved in t(4;11)(q21;q23) and t(11;19)(q23;p13) are localized on different adjacent NotI fragments by using pulsed-field gel electrophoresis (PFGE) analysis with the yeast artificial chromosome (YAC) clone yB22B2. The PFGE analysis using the YACs of YTY17 containing the prophobilinogen deaminase (PBGD), CBL2 and THY1 genes and yB22B2 allowed the following ordering of genes and breakpoints from CD3 to THY1 on 11q23: cent-CD3-ALL/MLL1-RCK-PBGD-CBL2-THY1, and the establishment of a long-range restriction map covering these genes. In addition, we showed that the FLI1 region involved in the t(11;22)(q24;q12) in Ewing's sarcoma was more telomeric region that the THY1 gene by analyzing somatic cell hybrids carrying the 11q- and/or 14q+ chromosome of the t(11;14)(q23;q32) translocation, and by PFGE analysis of the YAC clone YTY17.

Acute Disease↗
PubMed1993

Superoxide radical scavenging activity of phenolic compounds.

1. Superoxide radicals (O2-.) were generated from a hypoxanthin-xanthin oxidase (HPX-XOD) reaction system and detected by the electron spin resonance (ESR) spin-trapping technique. 2. The inhibitory effect on O2-. generation occurred in the order: superoxide dismutase (SOD) > L-ascorbic acid > eugenol > guaiacol > phenol. 3. And the second-order rate constants between O2-. and samples were: SOD 1.7 x 10(9)/M/S, L-ascorbic acid 3.4 x 10(5)/M/S, eugenol 8.3 x 10(3)/M/S, guaiacol 2.5 x 10(3)/M/S and phenol 5.8 x 10(2)/M/S. 4. It was clarified that the phenolic compounds have O2-. scavenging activity.

Ascorbic Acid↗
PubMed1993

[Experience with polyurethane intraurethral stents in aged patients].

A double Malecot-like 16F, polyurethane intraurethral catheter (IUC) was inserted 39 times in 25 patients between 68 and 91 years old (mean +/- SD: 77.5 +/- 5.5 years). Most of them were unfit for surgery because of severe illness or advanced age. All patients except 1 had either an indwelling catheter or a residual urine volume > 50ml at their first visit. The remaining one suffered from prostatic cancer and complained of pollakisuria and urinary incontinence. His symptoms were controlled well after ICU insertion and anticholinergic therapy. Twenty-nine insertions in 17 patients were considered successful, and the patients with successfully inserted stents voided without residual urine. Nine of 21 patients needed to take anticholinergic drugs. The mean duration of IUC use was 113 days in successful cases. In 9 out of 17 patients with an indwelling IUC for more than 112 days, the catheter became blocked by stones or clots. Therefore, we consider that the device should be changed after 110-120 days. Ten insertions failed for the following reasons: malposition, inappropriate IUC length, spontaneous migration to the bladder in patients with a short prostatic urethra, urinary retention due to underactive detrusor, and total incontinence and bleeding from prostatic cancer.

Aged↗