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Biomedical subjects

T Fujimura

Publications and source records attributed to T Fujimura.

At least 109 records · Page 6Linked to original sources
PubMed1998

Inactivation and destruction of conserved Trp159 of Fe-superoxide dismutase from Porphyromonas gingivalis by hydrogen peroxide.

The superoxide dismutase (SOD) of Porphyromonas gingivalis, an obligate anaerobe, was purified from Escherichia coli (sodA sodB mutant) harboring the P. gingivalis SOD-encoding gene. The purified protein contained both iron and a small amount of manganese. Iron- and manganese-reconstituted SOD, which contained one of these metals exclusively, showed specific activities of 1000 and 1200 U/mg/mol of metals/subunit, respectively. These values were similar to the specific activity of the native enzyme purified from the recombinant E. coli strain. The Fe-reconstituted enzyme was inactivated by 10 mM hydrogen peroxide to about 5% of its original activity after a 15 min incubation at 25 degrees C at pH 7.8, whereas the Mn-reconstituted enzyme showed no inactivation after 80 min. A concomitant increase in absorbance at 320 nm was observed with inactivation of the Fe-reconstituted enzyme. Amino acid analysis of the inactivated Fe-reconstituted enzyme showed a decrease of about 0.7 residues of tryptophan/subunit, a value similar to the iron content of the iron-reconstituted enzyme. Three major peptides of the digests of the purified SOD with lysylendopeptidase were separated by a reverse-phase HPLC monitoring at 280 nm. One of the peptides, corresponding to the residues from Gly149 to Lys176, decreased in the HPLC eluent of the H2O2-inactivated SOD to 20% of the amount measured for native SOD. Since this peptide contains only one tryptophan residue, it was concluded that the decomposed tryptophan residue is Trp159, which is located midway between the third and fourth metal ligands, Asp157 and His161, and is conserved in aligned amino acid sequences of all known Fe-SODs and Mn-SODs. Based on these results, we propose that the differences in hydrogen peroxide sensitivities observed for the Fe-SODs and Mn-SODs may be caused by the difference in the identity of the active site metal in the Fe-SODs and Mn-SODs and a tuning of the properties of the iron center in the Fe-SODs.

Amino Acid Sequence↗
PubMed1998

Association of a polymorphism of the endothelial constitutive nitric oxide synthase gene with myocardial infarction in the Japanese population.

We investigated the association between variations in the endothelial constitutive nitric oxide synthase (ecNOS) gene and the presence of myocardial infarction. The results indicate that the mutant allele (ecNOS'4a) is an independent risk factor for myocardial infarction in the Japanese population, especially in those lacking other conventional risk factors.

Aged↗
PubMed1998

Trypsinogen expression and early detection for peritoneal dissemination in gastric cancer.

BACKGROUND AND OBJECTIVES: The most reliable method for the diagnosis of peritoneal dissemination of gastric cancer at the present time is cytological examination of ascitic fluid, which is unavailable to patients without ascites or may be inadequate for those with ascites containing few cancer cells. It has been reported recently that human gastric cancer immunoreacted with a monoclonal antibody against pancreatic trypsinogen. We therefore examined the expression of trypsinogen as a new marker for the early diagnosis of peritoneal dissemination of gastric cancer. METHODS: Pancreatic trypsinogen protein was immunohistochemically stained with a three-step indirect immunoperoxidase method and cationic trypsinogen (trypsinogen-1) mRNA expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in gastric cancer. Twenty-nine of 30 primary tumors (97%) and all 12 tumors (100%) of the peritoneal seedings immunohistochemically reacted with trypsinogen. Preliminary study for early diagnosis of peritoneal dissemination was carried out for eight more recent patients who showed positive immunoreactivity to trypsinogen protein and expressed trypsinogen- mRNA in the primary tumor. The expression of trypsinogen-1 mRNA was detected by using peritoneal lavage fluid preoperatively collected in these patients. RESULTS: All three patients in whom peritoneal dissemination was diagnosed at the time of their operation(s) expressed trypsinogen-1 mRNA. One patient, who did not show peritoneal dissemination at the operation but was positive for trypsinogen-1 mRNA detection, later died of the recurrence of peritoneal dissemination. CONCLUSIONS: These results indicated that trypsinogen protein and trypsinogen-1 mRNA frequently expressed in peritoneal dissemination as well as primary tumors in gastric cancer and detection of trypsinogen-1 mRNA expression was a useful method for early diagnosis in peritoneal dissemination of gastric cancer.

Adenocarcinoma↗
PubMed1998

Identification of the G994--> T missense in exon 9 of the plasma platelet-activating factor acetylhydrolase gene as an independent risk factor for coronary artery disease in Japanese men.

Platelet-activating factor (PAF) acetylhydrolase may play important roles in the pathophysiology of thrombosis and atherosclerosis related to its catalytic action in the degradation of PAF and oxidized phospholipids. A missense mutation (G--> T transversion at nucleotide 994) in the plasma PAF acetylhydrolase gene results in a Val--> Phe substitution at amino acid 279 of the mature protein and a consequent loss of catalytic activity. However, the role of a deficiency or low activity of this enzyme caused by the missense mutation in the etiology of coronary artery disease (CAD) has not been determined. The relation between this mutation and the incidence of CAD in the Japanese population is investigated herein. The genotype of plasma PAF acetylhydrolase (MM, normal; Mm, heterozygote; and mm, deficient homozygote) was determined with a polymerase chain reaction (PCR) assay for 454 patients with myocardial infarction (MI) and 602 control subjects. The frequency of the m allele was significantly higher in male patients with MI (odds ratio, 1.8) than in controls, an association that was more marked in a low-risk subgroup (odds ratio, 2.3). In contrast, the m allele was not associated with MI in women. These results indicate that the G994--> T missense mutation in exon 9 of the plasma PAF acetylhydrolase gene is an independent risk factor for CAD in Japanese men, especially low-risk individuals, but not in women.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1998

Parallel stimulations of in vitro and in situ [35S]GTPgammaS binding by endomorphin 1 and DAMGO in mouse brains.

Metabotropic activities of endomorphin 1, a candidate for endogenous mu-opioid receptor ligands, were examined in comparison with the actions of [D-Ala2, N-Me-Phe4, Gly5ol]-enkephalin/DAMGO, a well-known synthetic mu-opioid agonist. Endomorphin 1 stimulated [35S]GTPgammaS binding to synaptic membranes from the mouse amygdala in a naloxone-reversible manner. DAMGO had the same effect in such preparations. In in situ [35S]GTP-gammaS binding experiments using brain sections, both endomorphin 1 and DAMGO similarly stimulated this binding in specific cellular locations throughout the brain regions. These findings strongly support the view that endomorphin 1 selectively acts on a mu-opioid receptor.

Amygdala↗
PubMed1998

Evaluation of tinnitus patients by peroral multi-drug treatment.

To evaluate patients complaining of subjective tinnitus, this study examined their response to peroral betahistine mesilate, vitamin B complex and diazepam in combination. Because three drugs were used together, it remains to be seen whether a single drug or a combination of drugs was effective. We issued questionnaires to 67 patients with tinnitus associated with sensorineural hearing loss of unknown etiology or tinnitus, despite normal hearing in pure tone audiometry and lack of distinct systemic disorders. Our original questionnaire contained seven items and allotted points for each item to facilitate evaluation. After prescribing the above drugs and observing patients' progress for 5 weeks, 50 of the 67 subjects were evaluated again by the same questionnaire. The present study evaluates tinnitus of patients as an example of clinical applications; this was not a controlled double blind study. It was found that, after patients took the prescribed medication, the total number of points were significantly reduced (paired t-test, P < 0.001). After medication, cases of bilateral tinnitus were significantly reduced from 27 to 14, and cases of two types of tinnitus sound, were significantly decreased from 22 to 11 (chi 2-test, P < 0.05). After 5 weeks of administration, 54% of patients felt treatment had been effective. Preliminary results suggest this peroral multi-drug treatment may provide relief for some patients with subjective tinnitus. However, long-term efficacy of the treatment was not investigated.

Administration, Oral↗
PubMed1998

Establishment of a new murine-phenotypic angiosarcoma cell line (ISOS-1).

A cell line, designated ISOS-1, was established from a tumor formed by transplantation of a human angiosarcoma into mice with severe combined immunodeficiency (SCID). The cells showed endothelial properties, based on the uptake of Dil-Ac-LDL and binding of UEA-I/GSA-I lectins, but were negative for CD11b and Pan Cytokeratin. However, the cells lost differentiated characteristics such as expression of von Willebrand factor, contact inhibition growth and tube formation activity. These findings indicate that ISOS-1 is a poorly-differentiated endothelial cell line. At the 81st passage, all of the cells were positive for H-2Dd in various intensity, but not HLA-ABC. The metaphase chromosomes consistently showed a characteristic mouse, but not human, telocentric form. Furthermore, this cell line produced fatal tumor growth in SCID mice and also in BALB/c mice. These results suggest that ISOS-1 is a murine-phenotypic angiosarcoma cell line.

Animals↗
PubMed1998

Prognostic significance of c-erbB-2 gene expression in the poorly differentiated type of adenocarcinoma of the stomach.

Prognostic significance of c-erbB-2 gene abnormalities is unclear in the poorly differentiated type of gastric carcinoma, because the abnormalities of this gene have been reported to be restricted to the differentiated type of gastric carcinoma. In this study, correlation of c-erbB-2 gene amplification/overexpression of mRNA and protein were studied in the poorly differentiated type of gastric carcinoma. c-erbB-2 gene amplification determined by the slot-blot hybridization was observed in 11 (13%) of 82 gastric cancer, and 8 of 11 tumors were poorly differentiated. In addition, c-erbB-2 mRNA expression was studied by the reverse transcriptase-polymerase chain reaction. Four (17%) of 24 tumors showed overexpression of c-erbB-2 mRNA, and all these four exhibited morphologically a poorly differentiated type. Among 157 poorly differentiated gastric cancers, 20 (13%) tumors showed immunohistochemically c-erbB-2 protein expression. These tumors had significantly higher incidences of larger tumor, serosal invasion-positive tumors, node-positive tumor, or peritoneal dissemination-positive tumor than those without c-erbB-2 expression. Furthermore, patients with c-erbB-2 protein overexpression ran poorer prognoses than those without c-erbB-2 expression. From these results, we conclude that expression c-erbB-2 tissue status may be a good prognostic indicator in poorly differentiated gastric carcinoma.

Adenocarcinoma↗
PubMed1998

Dissection of the effects of tumor necrosis factor-alpha and class II gene polymorphisms within the MHC on murine systemic lupus erythematosus (SLE).

Gene(s) in the MHC of the NZW strain (H-2z) up-regulate(s) systemic lupus erythematosus (SLE) in (NZB x NZW) F1 mice. So far, two plausible mechanisms have been implicated: (i) unique mixed haplotype class II molecules formed in the F1 mice act as a restriction element for self-reactive T cells and (ii) a unique polymorphism in the H-2-linked NZW tumor necrosis factor (TNF)-alpha allele which down-regulates TNF-alpha is contributory. Because of the difficulty in dissecting these alleles within the H-2 complex, it has not been determined which is indeed the case. We addressed this issue by establishing three different H-2-congenic (NZB x NZW) F1 mice bearing distinct haplotypes at class II and TNF-alpha regions, i.e. (NZB x NZW) F1 (H-2d/z:A(d/u)E(d/u)TNF(d/z)), (NZB x NZW.PL) F1 (H-2(d/u):A(d/u)E(d/u)TNF(d/d)) and (NZB x NZW.H-2d) F1 (H-2(d/d):A(d/d)E(d/d)TNF(d/d)). Among these, only (NZB x NZW) F1 produced a markedly lower level of TNF-alpha, due to the unique NZW TNF-alpha allele (TNF(z)). Studies of anti-DNA antibodies and lupus nephritis revealed that, compared to (NZB x NZW) F1, the disease of (NZB x NZW.H-2d) F1 was markedly reduced. In (NZB x NZW.PL) F1, the onset of renal disease was significantly delayed, while the extent of proteinuria and renal histopathology in individuals that had developed the disease was comparable to that seen in (NZB x NZW) F1. It seems likely that both class II and TNF-alpha gene polymorphisms are functioning as H-2-linked predisposing genetic elements, and that the TNF-alpha polymorphism acts to modulate an initial process of the renal disease.

Animals↗
PubMed1998

The significance of endothelin for generation of endocochlear potential.

The role of intermediate cells (ICs) in the stria vascularis (SV) of the cochlear ducts in the generation of endocochlear potential (EP) is clear because certain mutants cannot generate EP. Recent reports have shown that endothelin (ET) stimulates or inhibits the function of Na+, K(+)-ATPase in various organs. This study was designed to examine the immunocytochemical localization of ET and its receptor in the SV. The cochlear ducts of WBB6F1 (+/+) mice and mutants (W/Wv) devoid of the ICs were used for light and electron microscopic immunocytochemistry using rabbit anti-ET-1, ET-3, and ETA receptor antisera. The location of Na+, K(+)-ATPase using rabbit anti-rat Na+, K(+)-ATPase was also examined. Immunoreactivity to Na+, K(+)-ATPase was seen in the marginal cells (MCs) in both species. Immunoreactivity to ET-1 and ET-3 was preferentially localized in the rough endoplasmic reticulum and cytoplasmic vesicles of the ICs and along the plasma membrane of the ICs and in the MCs apposed to the ICs. Immunoreactive sites for ETA were almost identical to those of ET-1 and ET-3. Because Na+, K(+)-ATPase activities also exist in the MCs of the mutants, it appears likely that ET, synthesized and released by the ICs, may participate in generation of EP by regulating the function of Na+, K(+)-ATPase for production of the endolymph of the MCs.

Animals↗
PubMed1998

Local cytokine expression in steroid-modified tinea faciei.

In tinea faciei, a dermatophyte infection of the face, early stage lesions show erythema with crust and/or vesicles, a condition often misdiagnosed as dermatitis. Steroid application retards the healing in some cases and may induce penetration of the dermatophyte hyphae into hair and hair follicles. In the present study, we examined local immunity mediated by cytokines derived from lesional T lymphocytes in late stage of this disease. Interferon-gamma (IFN-gamma) and macrophage migration inhibitory factor (MIF) were highly expressed, but neither interleukin-4 (IL-4) nor interleukin-5 (IL-5) could be detected by RT-PCR using cryosections. These data suggested that IFN-gamma and MIF may be important in the delayed-type hypersensitivity (DTH) response against the fungus in the hair follicle in late stages.

Adult↗
PubMed1998

Cepharanthine inhibits proliferation of cancer cells by inducing apoptosis.

Cepharanthine, a biscoclaurine alkaloid extracted from Stephania cepharantha Hayata was examined for a possible apoptosis-inducing effect in murine P388 doxorubicin-sensitive (P388/S) and -resistant (P388/DOX) cells. A significant increase in LDH release from cells was observed after P388/S and P388/DOX cells had been exposed to cepharanthine for 24 h. Cepharanthine (10 micrograms/ml) markedly induced apoptosis in resistant cells after 6 h and 24 h. By the means of agarose electrophoresis the DNA ladder was detected in cell lines treated with cepharanthine for 24 h. Cepharanthine (1-10 micrograms/ml) also induced the production of reactive oxygen species in P388/DOX cells, while no such cepharanthine-induced increase in reactive oxygen species was observed in P388/S cells. Flow cytometry analysis showed a high level of Fas-antigen expression in P388/DOX cells treated with cepharanthine. Furthermore, we found that the inhibitition of DNA and protein synthesis caused by cepharanthine (10 micrograms/ml) was more significant in resistant cells than in sensitive cells. Cepharanthine had no effect on the GSH content of P388/S and P388/DOX cells. Our experimental results suggest that cepharanthin can induce apoptosis both in P388/S and P388/DOX cells, especially in the latter. Apoptosis induced by cepharanthine may be implicated in the production of reactive oxygen species and Fas-antigen expression in tumor cells.

Alkaloids↗
PubMed1998

A retrospective cohort study on retirement and mortality for male employees of a local government of Japan.

This retrospective cohort study describes the mortality pattern after retirement and examines associations of the last job position and work status immediately after retirement with the mortality for male employees who retired from Kochi prefectural government. The subjects include 514 retirees over the 1977-1981 period, who were followed for 9.8 years after retirement, and 721 retirees over the 1982-1986 period, who were followed for 5.8-9.8 years. All subjects were hypothesized to have retired at a normal retirement age. Mortality risk was stable through the follow-up period subdivided into two-year intervals in both cohorts of retirees. In both cohorts, men who did not work immediately after retirement had increased mortality within the first two years of retirement compared with those who worked immediately after retirement. This finding is consistent with the mortality pattern explained by health related selection into working after retirement. The present study does not show a meaningful mortality fluctuation over the post-retirement period among male employees of the local government. Lack of information on ages and health status at retirement of individual subjects hampers discussion about causality of observed associations between two study variables concerning pre- and post-retirement characteristics and post-retirement mortality.

Aged↗
PubMed1998

[The expression of cMET/hepatocyte growth factor receptor in colorectal cancer].

In this study, we estimated the expression of c-MET/Hepatocyte Growth Factor receptor in colorectal cancers by immunohistochemistry. In 118 patients, c-MET wee expressed in 65 patients (55%). About the clinicopathological findings of metastasis, the proportion of c-MET-positive in the patients with liver metastasis, 78% (18/23), was significantly higher than that without liver metastasis, 49% (47/95), but there was no significant difference about lymph node metastasis and peritoneal dissemination. About the pathological findings of primary lesion, the proportion of c-MET-positive in the patients with infiltration into lymphatic vessels, 63% (48/76), was significantly higher than that without infiltration, 40% (17/42), but there was no significant difference about infiltration into veins. The proportion of c-MET-positive increased as the tumor stage proceeded from t1 to t4 and as the histopathological stage proceeded from I to IV. These results suggest that c-MET may play an important role in the growth and scattering of colorectal cancer cells.

Adenocarcinoma↗
PubMed1998

Origin and evolution of twin microsatellites in the genus Oryza.

An ancestral sequence of twin microsatellites of rice was found in a wild species. Twin microsatellite loci, RM20A and RM20B, were located on separate regions of chromosomes 11 and 12, which had been duplicated during rice evolution. These twin microsatellites showed different allele diversities in A genome species of the genus Oryza. This difference was caused by repetition of a simple sequence consisting of (TAA)n. Oryza longistaminata contains a short poly(A) sequence in this region instead of the poly(TAA) found in other species. A sequence comparison of RM20-related amplicons suggested that the poly(A)-containing sequence is the ancestral sequence of the RM20A and RM20B microsatellites. A simple base substitution in the poly(A) sequence may have produced the longer microsatellite motif (TAA). This mutation may have occurred on one of the chromosomes of a hypothetical ancestor of the A genome species before duplication of the chromosome segments.

Alleles↗
PubMed1997

Separation of 18 6-aminoquinolyl-carbamyl-amino acids by ion-pair chromatography.

Eighteen 6-aminoquinolyl-carbamyl (AQC)-amino acids were separated by ion-pair chromatography, using tetrabutylammonium (TBA) as a counterion. Optimum separation was obtained on a C8 reverse-phase column using gradient elution with two mobile phases, A (5 mM TBA, 75 mM ammonium acetate, pH 7.5) and B (80% acetonitrile). The AQC-amino acids were detected by fluorescence with excitation at 250 nm and emission at 395 nm, and the analysis time was 65 min. The response factors of individual AQC-amino acids to AQC-phenylalanine ranged from 0.42 to 1.08 (except for tryptophan at 0.01), with an average of 0.8. Detection limits by fluorescence ranged from 11.8 fmol (threonine) to 51.7 fmol (methionine), except for tryptophan (1.8 pmol).

Amino Acids↗