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Biomedical subjects

S Tajima

Publications and source records attributed to S Tajima.

At least 109 records · Page 6Linked to original sources
PubMed2000

Topical delta-aminolevulinic acid-based photodynamic therapy for Japanese actinic keratoses.

Based on the opinion that 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) may be disadvantageous to Oriental patients with dark skin, including Japanese, because the competing chromophore melanin inhibits the photochemical reaction, we assessed the therapeutic effects when Japanese AK were treated with ALA-PDT. Fifty-three lesions in ten patients were followed up for over one year. The cure rates of AK on the face including the neck and on extremities were 81.8% and 55.6%, respectively. The results were approximately the same cure rates as those reported for AK in Caucasian patients. However, a larger number of treatment sessions were required. In the red light range, incoherent light including 630 nm and 670 nm is superior to 630 nm laser light.

Aged↗
PubMed2000

The region between amino acids 245 and 265 of the bovine leukemia virus (BLV) tax protein restricts transactivation not only via the BLV enhancer but also via other retrovirus enhancers.

Bovine leukemia virus (BLV) is associated with enzootic bovine leukosis and is closely related to human T-cell leukemia virus type 1 (HTLV-1). The Tax protein of BLV acts through the 5' long terminal repeat (LTR) of BLV and activates the transcription of BLV. In this study, we amplified tax genes from BLV-infected cattle using PCR. We cloned the genes and monitored the transcriptional activities of the products. Seven independent mutant Tax proteins, with at least one amino acid substitution between residues 240 and 265, exhibited a markedly stronger ability to stimulate the viral LTR-directed transcription than the wild-type Tax protein. Analysis of chimeric Tax proteins derived from wild-type and mutant Tax proteins clearly demonstrated that a single substitution between residue 240 and 265 might be critical for the higher activities of the Tax mutant proteins. Furthermore, it appeared that transient expression of a Tax mutant protein was better able to increase the production of viral proteins and particles from a defective recombinant proviral clone of BLV than was wild-type Tax. Analysis of mutations within the U3 region of the LTR revealed that a cyclic AMP-responsive element in Tax-responsive element 2 might be sufficient for the enhanced activation mediated by the mutant proteins. In addition to the LTR of BLV, other viral enhancers, such as the enhancers of HTLV-1 and of mouse mammary tumor virus, which cannot be activated by wild-type BLV Tax protein, were activated by a Tax mutant protein. Our observations suggest that the transactivation activity and target sequence specificity of BLV Tax might be limited or negatively regulated by the region of the protein between amino acids 240 and 265.

Animals↗
PubMed2000

[GC-MS determination of l-ephedrine and d-pseudoephedrine in human plasma].

To determine l-ephedrine (E) and d-pseudoephedrine (PE) concentrations in human plasma simultaneously, we used a selected-ion monitoring method with gas chromatography-mass spectrometry (GC-MS) using deuterium-labeled E and PE as internal standards. The E and PE in human plasma were extracted with hexane-ethylacetate (9/1) under alkaline conditions and were easily converted into their heptafluorobutyryl derivatives by treating with heptafluorobutyrylimidazole. The calibration curves of E and PE showed a good linearity in the range from 0.82 to 81.9 ng/ml for E, and from 0.41 to 41.0 ng/ml for PE, respectively. The limit of detection was 0.82 ng/ml for E and 0.41 ng/ml for PE in human plasma, respectively.

Ephedrine↗
PubMed2000

Tranilast inhibits cell proliferation and collagen synthesis by rabbit corneal and Tenon's capsule fibroblasts.

PURPOSE: To determine whether tranilast, N-(3,4-dimethoxycinnamoyl) anthranilic acid, influences cell proliferation and collagen synthesis by rabbit Tenon's capsule fibroblasts (TFs) and corneal stromal fibroblasts (CFs). METHODS: Rabbit TFs and CFs (7000 cells/well) were cultured in F-12 nutrient mixture supplemented with 1% FBS, plus 0, 3, 30, or 300 microM tranilast, and the number of cells was counted 72 hrs later. To determine the effect of tranilast on collagen synthesis, cells at confluence were cultured in a medium containing 0, 3, 30, or 300 microM tranilast and labeled with 3H-proline, and the amount of radioactivity incorporated into collagenase-sensitive proteins was measured. RESULTS: At 300 microM, tranilast decreased the number of TFs by about 27% and the number of CFs by about 45%, but had no effect on cell viability. The same concentration of tranilast reduced TFs collagen synthesis and CFs collagen synthesis. CONCLUSIONS: Tranilast may inhibit scar formation after trabeculectomy for glaucoma and after excimer laser photorefractive keratectomy.

Animals↗
PubMed2000

[PL granule-induced pneumonia requiring mechanical ventilation].

PL granule is one of the most common forms of composite medicine for colds in Japan, including acetaminophen. We report a case of PL granule-induced pneumonia that required mechanical ventilation. A 72-year old man who had been prescribed amiodarone for more than one year before for arrhythmogenic right ventricular dystrophy, repeatedly took PL granules at one-week intervals because of sneezing and fever. He then underwent acute respiratory failure. He needed mechanical ventilation for severe hypoxemia, but recovered with glucocorticoid pulse therapy. Because the blastoid transformation test using his peripheral blood lymphocytes was positive on stimulation with PL granules, but negative on amiodarone stimulation, he was diagnosed as having drug (PL granule)-induced pneumonia. Only one case of PL granule-induced pneumonia and seven of acetaminophen-induced pneumonia have been reported. None of these patients needed mechanical ventilation. PL granule-induced pneumonia should be treated cautiously because of possible acute exacerbation.

Aged↗
PubMed2000

Pulmonary nocardiosis during immunosuppressive therapy for idiopathic pulmonary fibrosis.

Nocardiosis is a subacute or chronic suppurative infection caused by Nocardia species. Although it is more common in immunocompromised hosts, idiopathic pulmonary fibrosis (IPF) has not been recognized as a predisposing factor for nocardial infection. We report a case of IPF, in which pulmonary nocardiosis developed during treatment with prednisolone and cyclophosphamide. The risk of pulmonary nocardiosis may be increased in cases of IPF on immunosuppressive therapy. Since IPF often accompanies lung carcinoma, it is important to correctly differentiate nocardiosis from carcinoma.

Aged↗
PubMed1999

Isolation of the novel cDNA of a gene of which expression is induced by a demethylating stimulus.

We have isolated a novel cDNA clone, named AZ2, from a cDNA library of mRNA prepared from C3H10T1/2 cells that had been transiently exposed to 5-azacytidine, a potent inhibitor of DNA methyltransferase. The elucidated nucleotide sequence revealed that the 5' region of the cDNA was rich in the CpG sequence. The AZ2 cDNA contained a 1215-nucleotide open reading frame, and the expected amino acid sequence had a molecular mass of 46090. The amount of the transcript increased on 5-azacytidine treatment of C3H10T1/2 cells, and the transcript was significantly expressed in mouse testis, brain, lung, kidney, heart and ovary. Specific antibodies raised against a fusion protein including glutathione S-transferase revealed a band of an approximately 48kDa translation product for testis, brain, lung, and cultured cells that ectopically expressed the AZ2 protein. The AZ2 protein was mainly localized in the cytoplasm. The amino-terminal part of the AZ2 protein was homologous to the previously reported TANK (Cheng and Baltimore, 1996. Genes Dev. 10, 963-973) and I-TRAF (Rothe, 1996. Proc. Natl. Acad. Sci. USA 93, 8241-8246), which participate in the signal transduction cascade from the tumor necrosis factor-receptor to the transcription factor, NFkappaB. Overexpression of AZ2 inhibited TNF alpha mediated NFkappaB activation. AZ2 could be a component of a regulator of the NFkappaB activation cascade.

Amino Acid Sequence↗
PubMed1999

Constitutive expression of mRNA for the same choline acetyltransferase as that in the nervous system, an acetylcholine-synthesizing enzyme, in human leukemic T-cell lines.

Both muscarinic and nicotinic acetylcholine (ACh) receptors are known to be present on the surface of lymphocytes. We have shown that variable amounts of ACh are detectable in the blood of various mammals including humans, and a major portion of blood ACh is localized in circulating mononuclear leukocytes in humans. In order to investigate which types of blood cell are the source of ACh in human blood, expression of mRNA for choline acetyltransferase (ChAT, EC 2.3.1.6), which catalyzes ACh synthesis, was analyzed using human leukemic cell lines as models of lymphocytes and the reverse transcription-polymerase chain reaction (RT-PCR) method. We observed that mRNA for the same ChAT as that in the nervous system is expressed constitutively in all the T-cell lines tested, but not in B-, pre-lymphoma or monocytic cell lines. Furthermore, only T-cell lines showed high ACh-synthesizing activities and intracellular ACh contents. These results suggest that the major portion of ACh in the circulating blood originates from T-lymphocytes.

Acetylcholine↗
PubMed1999

Elimination of difluorocarbene from the molecular ions of alpha, alpha,alpha-trifluorocresols with a fluorine atom migration in an ion trap mass spectrometer.

The elimination of difluorocarbene (CF(2)) from the molecular ions of m-alpha,alpha,alpha-trifluorocresol (MW 162, 1) and p-alpha, alpha, alpha-trifluorocresol (MW 162, 2) upon electron impact have been investigated using a quadrupole ion trap mass spectrometer. This reaction involves a fluorine (F) atom migration from the trifluoromethyl group to the benzene ring. In the case of 1, an F atom migrates via a four-membered ring transition state to give rise to the molecular ion of p-fluorophenol (MW 112, 5) and a small amount of o-fluorophenol (MW 112, 3). On the other hand, in the case of 2, an F atom migrates to the ipso position of the benzene ring via a three-membered ring transition state to give rise to 5(+). These conclusions were confirmed by the comparison of the energy-resolved mass spectra (collision-induced dissociation (CID) spectra versus collision energy) of the m/z 112 ions from 1(+) and 2(+) with those of reference compounds, o-, m- and p-fluorophenol (3-5).

Cresols↗
PubMed1999

Alginate oligosaccharides stimulate VEGF-mediated growth and migration of human endothelial cells.

Alginate oligosaccharides cleaved from alginic acid polysaccharides of seaweed were tested to determine their ability to enhance proliferation and migration of human umbilical vein endothelial cells. A mixture of alginate oligosaccharides (5 microg/ml in culture broth) stimulated endothelial cell growth, [(3)H]thymidine uptake and migration in the presence of recombinant vascular endothelial growth factor 165 (VEGF(165)). In contrast, a high concentration mixture of the oligosaccharides ( approximately 100 microg/ml) suppressed cell growth. The stimulatory activity was comparable to that of heparin, with affinity to VEGF(165), and decreased on heparin-induced stimulation. Each effective oligosaccharide had guluronic acid at the reducing end. A mixture of alginate oligosaccharides (5 microg/ml) and the most paragraph signeffective fraction (1 microg/ml) stimulated endothelial cell migration. In the presence of VEGF and heparin, some alginate oligosaccharides with the peripheral guluronic acid demonstrated marked stimulatory effects, and one fraction also showed a migratory effect. These findings indicate novel activities of alginate oligosaccharide(s) in endothelial cell growth and migration and suggest synergistic and/or stabilizing effects on VEGF(165)-dependent stimulation of endothelial cells.

Alginates↗
PubMed1999

Coordinated distribution patterns of three enzyme activities involved in the absorption and metabolism of beta-carotene and vitamin A along the villus-crypt axis of chick duodenum.

The conversion of beta-carotene to retinal and the succeeding metabolic process of the retinal leading to production of retinol and retinyl esters are the prerequisite for the utilization of beta-carotene as a provitamin A. These processes are participated by beta-carotene cleavage enzyme, retinal reductase and retinol esterifying enzyme(s) in the small intestine. To examine whether these enzymes exhibit the coordinated distribution in the villus, we have used the cryostat sectioning technique to quantify the activities of beta-carotene cleavage enzyme, retinal reductase and retinol esterifying enzymes along the villus-crypt axis in 8-day-old chick duodenum. The beta-carotene cleavage enzyme activity was very low in the crypt and gradually increased, reaching a maximum in the mid-villus. The villus-crypt gradient of the beta-carotene cleavage enzyme activity corresponded with those of retinal reductase activity and lecithin: retinol acyltransferase (LRAT) activity, but distinct from that of acyl-CoA: retinol acyltransferase (ARAT) activity. Furthermore, the distribution of the content of retinyl esters was similar to that of LRAT activity. These results suggest that the beta-carotene cleavage enzyme is coordinately distributed along the villus-crypt axis with retinal reductase and LRAT, the two enzymes which require cellular retinol-binding protein, typeII (CRBPII) as the donor of the substrate.

Acyltransferases↗
PubMed1999

Accuracy of integration of dental casts in three-dimensional models.

PURPOSE: This study investigated errors occurring in three-dimensional (3D) models when plaster dental casts are integrated into them. MATERIALS AND METHODS: Three-dimensional milling models of three patients with a jaw deformity were fabricated using the Endoplan system (SPARC International Inc, Santa Clara, CA). After this, plaster dental casts were integrated into the 3D models using a face-bow transfer system. Two cephalograms were then compared, one obtained from the patient and the other obtained from the 3D model painted with contrast medium. RESULTS: In two cases, the reproducibility of the dental position as determined by angle analysis was within 2 degrees, and that determined by distance analysis was within 2 mm. However, errors over 4 degrees and 4.2 mm, respectively, were observed in one case. CONCLUSION: It is clinically important to confirm the accuracy of the 3D model by cephalometric analysis, and it may be necessary to reposition the dental model based on the results.

Adult↗
PubMed1999

Purification and characterization of a beta-glucosidase with beta-xylosidase activity from Aspergillus sojae.

A beta-glucosidase (EC 3.2.1.21) was purified as an electrophoretically homogeneous protein from a solid culture of Aspergillus sojae. The molecular mass of the purified enzyme was estimated to be 250 kDa by gel filtration chromatography and 118 kDa by sodium dodecyl sulfate--polyacrylamide gel electrophoresis (SDS-PAGE). The isoelectric point of the enzyme was 3.80. The maximum velocity of rho-nitrophenyl beta-d-glucopyranoside degradation by the beta-glucosidase was attained at 60 degrees C and at pH 5.0. The purified enzyme was stable from pH 6.0 to 8.0, and up to 50 degrees C. The activity of the enzyme was significantly inhibited by Hg2+ and Cu2+, and stimulated by Mn2+ and Fe3+. The purified enzyme hydrolyzed beta-D-xylopyranosides as well as beta-D-glucopyranosides; the Km and Vmax values on rho-nitrophenyl beta-D-glucopyranoside were 0.14 mM and 16.7 micromol/min/mg protein, and on rho-nitrophenyl beta-D-xylopyranoside 0.51 mM and 12.2 micromol/min/mg protein, respectively.

Journal Article↗
PubMed1999

Subsite affinities of beta-glucosidase from Aspergillus sojae on various xylooligosaccharides.

The subsite affinities of beta-glucosidase (EC 3.2.1.21) with high beta-xylosidase activity from Aspergillus sojae on various xylooligosaccharides (degree of polymerization: n = 2-6) were investigated by steady-state kinetic analysis. The molecular activity (k0) value of the enzyme for xylobiose was not markedly different from those of other substrates (n = 3-6). The arrangement of the subsite affinities (A(i), i = 1-6) was evaluated; A1 = 2.93 kcal/mol, A2 = 3.67 kcal/mol, A3 = 0.64 kcal/mol, A4 = 0.12 kcal/mol, A5 = -0.07 kcal/mol, A6 = -0.05 kcal/mol, and the intrinsic rate constant (K(int)) was 7.6 s(-1). The subsite structure was similar to those of beta-glucosidase from A. niger and alpha-glucosidases from A. niger and Mucor javanicus, where the values for A1 were much larger than those for A3.

Journal Article↗
PubMed1999

Dyschromatosis symmetrica hereditaria (reticulate acropigmentation of Dohi): report of a Japanese family with the condition and a literature review of 185 cases.

We report a Japanese family with dyschromatosis symmetrica hereditaria (DSH) (MIM 127400 in McKusick's Mendelian Inheritance in Man), a rare autosomal dominant genodermatosis, predominantly occurring among Japanese and Korean individuals. Members of the present family affected with the disease showed a mixture of hyperpigmented and hypopigmented macules distributed on the face and the dorsal aspects of the extremities, which are typical of DSH. As most of the literature on DSH has been written in Japanese, dermatologists outside Japan are not familiar with the condition. In this paper, 185 cases of DSH, most of them reported in Japanese, are reviewed and unique clinical, histological and genetic features of this condition are delineated.

Child↗