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Biomedical subjects

T Umemoto

Publications and source records attributed to T Umemoto.

At least 73 records · Page 4Linked to original sources
PubMed1995

Effect of T-cell deficiency on the formation of periapical lesions in mice: histological comparison between periapical lesion formation in BALB/c and BALB/c nu/nu mice.

The role of T-cells in the development of periapical lesions was investigated immunohistochemically using 16 normal (BALB/c) mice and 16 nude (BALB/c nu/nu) mice (congenitally T-cell-deficient mice). The pulp chambers of maxillar first molars of all mice were opened, and the infiltrated immunocytes (anti-Thy1.2, -Lyt-1, -Lyt-2, -L3T4, -I-Ad, -IgG, and -IgM positive cells) were determined immunohistochemically at 2, 4, 6, and 8 wk after operation. Periapical lesions appeared at 2 wk in both mouse groups. Numerous anti-I-Ad positive-stained cells appeared at 2 wk, anti-I-Ad, -Thy1.2 (-Lyt-1, -L3T4), -IgG positive-stained cells appeared between 4 and 8 wk, and periapical lesions with bone resorption rapidly increased until 4 wk in normal mice. On the other hand in nude mice, only anti-I-Ad and -IgG positive cells were present from 4 to 6 wk, and the progress of periapical lesions with inflammatory cells stopped at 6 wk. Furthermore, numerous fibroblasts were found instead of inflammatory cells at 8 wk. These findings suggest that the progression of periapical lesions with bone resorption required helper T-cells and numerous immunoglobulin-producing cells.

Animals↗
PubMed1995

Inflammatory cytokine gene expression in human periodontal ligament fibroblasts stimulated with bacterial lipopolysaccharides.

The effects of Porphyromonas gingivalis lipopolysaccharide (P-LPS) and Escherichia coli lipopolysaccharide (E-LPS) on the gene expression and production of inflammatory cytokines of human periodontal ligament fibroblasts (HPLF) were examined by a Northern (RNA blot) assay and enzyme-linked immunosorbent assay, respectively. mRNAs for interleukin-6 (IL-6), IL-8, and transforming growth factor beta (TGF-beta) were detected in HPLF cells, but IL-1 alpha, IL-1 beta, tumor necrosis factor alpha, transforming growth factor alpha, and granulocyte-macrophage colony-stimulating factor were not detected by reverse transcription-PCR. The expression of TGF-beta mRNA was not influenced by either LPS. P-LPS (1 to 10 micrograms/ml) and E-LPS (100 micrograms/ml) markedly stimulated the expression of IL-6 and IL-8 mRNAs compared with the control. The synthesis of IL-6 and IL-8 was also stimulated by 10 and 100 micrograms of both LPSs per ml, but IL-8 synthesis was not stimulated with E-LPS at 1 microgram/ml. Secretion of IL-6 and IL-8 into the culture medium was detected at 6 and 3 h, respectively, after exposure to P-LPS (10 micrograms/ml). These findings suggested that P. gingivalis leads to periodontal tissue destruction and alveolar bone resorption through IL-6 and IL-8 released from HPLF cells stimulated with its LPS.

Alkaline Phosphatase↗
PubMed1995

Structural study on the free lipid A isolated from lipopolysaccharide of Porphyromonas gingivalis.

The chemical structure of lipid A isolated from Porphyromonas gingivalis lipopolysaccharide was elucidated by compositional analysis, mass spectrometry, and nuclear magnetic resonance spectroscopy. The hydrophilic backbone of free lipid A was found to consisted of beta(1,6)-linked D-glucosamine disaccharide 1-phosphate. (R)-3-Hydroxy-15-methylhexadecanoic acid and (R)-3-hydroxyhexadecanoic acid are attached at positions 2 and 3 of the reducing terminal residue, respectively, and positions 2' and 3' of the nonreducing terminal unit are acylated with (R)-3-O-(hexadecanoyl)-15-methylhexadecanoic acid and (R)-3-hydroxy-13-methyltetradecanoic acid, respectively. The hydroxyl group at position 4' is partially replaced by another phosphate group, and the hydroxyl groups at positions 4 and 6' are unsubstituted. Considerable heterogeneity in the fatty acid chain length and the degree of acylation and phosphorylation was detected by liquid secondary ion-mass spectrometry (LSI-MS). A significant pseudomolecular ion of lipid A at m/z 1,769.6 [M-H]- corresponding to a diphosphorylated GlcN backbone bearing five acyl groups described above was detected in the negative mode of LSI-MS. Predominant ions, however, were observed at m/z 1,434.9 [M-H]- and m/z 1,449.0 [M-H]-, each representing monophosphoryl lipid A lacking (R)-3-hydroxyhexadecanoic and (R)-3-hydroxy-13-methyltetradecanoic acids, respectively. The presence of mono- and diphosphorylated lipid A species was also confirmed by LSI-MS of de-O-acylated lipid A (m/z 955.3 and 1,035.2, respectively).

Carbohydrate Sequence↗
PubMed1995

[A new modality of locoregional chemotherapy based on biochemical double modulation of 5-fluorouracil with both leucovorin and cisplatin against liver metastases of colorectal cancer].

A new modality of locoregional chemotherapy based on biochemical double modulation of 5-fluorouracil (FU) with both leucovorin (LV) and cisplatin (CDDP) against liver metastases of colorectal cancer was devised. The schedule for the locoregional therapy was as follows; bolus infusion of LV (6 mg/body) followed by 30-minute infusion of CDDP (10 mg/body) and 30-minute infusion of 5-FU (250 mg/body). Four colorectal cancer patients with numerous metastases to both lobes of liver were given intraarterial administration of above anticancer drugs every 1-2 weeks after resection of primary lesions. On the one hand, 3 colorectal cancer patients, who developed a few metastases to both lobes of liver, were treated preventively by the same schedule every 2-3 weeks after the resection of metastatic tumors. As for the clinical (radiographic) response, complete response and partial response were observed in 1 and 2 of 4 patients, respectively. The response rate was 75%. No new lesions appeared for over 1 year by the preventive treatment in 2 of 3 patients, whereas new lesions appeared in one patient at 3 months after discontinuation of treatment because of mild toxicity. The toxicity, however, was within acceptable limits. These results indicated that biochemical double modulation of 5-FU with both LV and CDDP is a very promising locoregional chemotherapy against liver metastases of colorectal cancer.

Aged↗
PubMed1995

[A study on the relationship between clinicopathological findings of gastric cancer and its biological behavior such as DNA ploidy pattern and immunohistochemical staining of PCNA, laminin, p53 and nm 23].

UNLABELLED: The quantity of DNA ploidy and the expression of PCNA, laminin, p53 and nm23 by immunohistochemical stain were investigated using paraffin-embedded specimens obtained from 135 gastric cancer patients, and were compared with clinicopathological findings. RESULTS: (1) The incidence of DNA high ploidy (HP) was significantly higher in such a case with infiltrating type (INF) and positive lymph node metastasis (p+) compared with that of negative cases. (2) The high level of PCNA labeling index (HLI), negative expression of laminin (NEL) and nm23 (NE23) were more frequently observed in INF; large tumor size, deep invasion and p+, while positive p 53 was noted only in p+ cases. (3) The survival curve of HP, HLI, NEL, and NE 23 was significantly lower than that of the cases showing the reverse findings. As a conclusion, it is suggested that the investigation of the DNA ploidy, PCNA, laminin, p53 and nm23 might be useful as a parameter of biological behavior for gastric cancer and the prognosis of gastrectomized patients.

DNA, Neoplasm↗
PubMed1995

[A case of successful surgical treatment of recrudescent stanford type A aortic dissection after early thrombogenic closure and reduction of dissecting lumen].

A 51-year-old woman was admitted with acute chest and back pain. A CT scan (2 hours after onset) was demonstrated acute type A aortic dissection. The dissecting lumen was already closed with thrombus. A DSA was performed. It showed no intimal tear and a normal aortic figure. Repeat CT (5 hours after onset) was performed. It showed reduction of dissecting lumen compared with previous CT. Although medical treatment was continued, she recomplained intermittent slight chest and back pain. On the sixteenth day after her admission, repeat CT revealed recrudescent dissection and opened dissecting lumen of ascending aorta. Graft replacement was successfully performed using circulatory arrest and retrograde cerebral perfusion. She was discharged in good health.

Acute Disease↗
PubMed1994

Binding of host-associated treponeme proteins to collagens and laminin: a possible mechanism of spirochetal adherence to host tissues.

The polypeptides of seven strains of human treponemes were investigated by immunoblot analysis for their binding to the human placental collagens and laminin. Of the treponemal polypeptides, eleven polypeptides, 45-kDa, 49-kDa, and 62-kDa polypeptides from T. pallidum ATCC 27087, a 48-kDa polypeptide from T. phagedenis biotype Reiter, 51-kDa and 53-kDa polypeptides from T. vincentii ATCC 35580, 30-kDa, 53-kDa and 63-kDa polypeptides from T. socranskii subsp. buccale ATCC 35534, a 52-kDa polypeptide from T. denticola ATCC 35405, and a 53-kDa polypeptide from T. denticola ATCC 33520 possessed an ability to bind to the laminin, type I, III, IV, or V collagen. An intermediate-sized human oral isolate strain G7201 did not possess any laminin- or collagen-binding polypeptides. Immunoelectron microscopy using intact treponemal cells with a single collagen-binding polypeptide and the corresponding antisera demonstrated that the 51-kDa and 53-kDa polypeptides from T. vincentii, the 53-kDa polypeptide from T. socranskii subsp. buccale ATCC 35534 and the 52-kDa polypeptide from T. denticola ATCC 35405, were outer envelope proteins.

Bacterial Adhesion↗
PubMed1994

Construction and characterization of a fimA mutant of Porphyromonas gingivalis.

Although fimbriae of Porphyromonas gingivalis have been implicated as playing a major role in adherence to gingival tissue surfaces, no conclusive genetic evidence has yet been obtained. The fimA gene, the determinant for the major fimbrial subunit protein, was cloned and sequenced (D. P. Dickinson, M. A. Kubiniec, F. Yoshimura, and R. J. Genco, J. Bacteriol. 170:1658-1665, 1988). We undertook to inactivate the fimA gene by a homologous recombination technique and examined the fimA mutant for changes in surface properties, including production of fimbriae, adherence to human gingival fibroblasts and epithelial cells, hemagglutinating activity, and surface hydrophobicity. To inactivate the fimA gene, we disrupted a fimA clone by insertion of a DNA segment containing an erythromycin resistance (Emr) gene. This was then delivered into P. gingivalis ATCC 33277 from an Escherichia coli K-12 strain, SM10 lambda pir, by using a mobilizable suicide vector, pGP704; recombination at the fimA locus led to the isolation of a fimA mutant. Disruption of the fimA locus and disappearance of FimA production were confirmed by Southern hybridization with a fimA-specific DNA probe and Western immunoblotting with a monoclonal antibody against the FimA protein, respectively. The fimA mutant constructed failed to express long (0.5- to 1.0-micron) fimbriae from the bacterial surface and had a diminished adhesive capacity to tissue-cultured human gingival fibroblasts and epithelial cells. Observation of the bacteria adhering to human gingival fibroblasts by scanning electron microscopy revealed that the wild-type strain had dramatic local changes in the appearance of the microvilli at the point of contact with large bacterial clumps, whereas the fimA mutant did not. In contrast, neither the hemagglutinating activity nor the surface hydrophobicity was changed in the fimA mutant. These data thus constitute the first direct genetic evidence demonstrating that the FimA protein of P. gingivalis is essential for the interaction of the organism with human gingival tissue cells through a function(s) encoded by the fimA gene.

Bacterial Adhesion↗
PubMed1994

The effect of root conditioning with minocycline HCl in removing endotoxin from the roots of periodontally-involved teeth.

Noting the acid-conditioning effect of minocycline on the root surface, we investigated the ability of minocycline to remove endotoxin on untreated, diseased cementum in vitro. Root surface specimens affected by periodontal disease were immersed in minocycline solution (10 mg/ml, 50 micrograms/ml, and 5 micrograms/ml) for 10 minutes, 1 day, 3 days, and 7 days, and endotoxin eluted was determined by the limulus amoebocyte lysate (LAL) assay. Specimens serving as controls were treated by immersion in pyrogen-free water, agitation, polishing, or exposure to citric acid (pH 1.0) for 3 minutes. When the period of immersion was the same, the root treatment with minocycline (10 mg/ml) yielded a significantly higher rate of neutralization of endotoxin than that with a 5 micrograms/ml or 50 micrograms/ml solution. However, the detoxifying effect of this method was less adequate than that of polishing or treatment with citric acid solution. There was variability in the effects of polishing among the teeth tested. To obtain the expected effect of the root treatment with minocycline solution; i.e., removal of the endotoxin, the combining of minocycline with a mechanical root preparation, such as polishing or root planing, seems to be effective.

Analysis of Variance↗
PubMed1994

[Successful surgical correction of endocardial cushion defect in a 64-year-old female patient].

We have experienced a surgical correction of ECD of a 64-year-old female patient. The preoperative left ventriculogram showed typical goose-neck deformity of the left ventricle and mild mitral regurgitation. The correction consisted of repair of the mitral cleft, and patch closure of the ostium primum. Postoperative course was uneventful. The operation of ECD should be recommended even in an older patient.

Cardiac Catheterization↗
PubMed1994

[Studies on adjuvant chemotherapy using subserosal or submucosal administration of neocarzinostatin for gastric cancer and colorectal cancer].

The significance and effectiveness of adjuvant intraoperative chemotherapy using subserosal or submucosal administration of Neocarzinostatin (NCS) and CH 40 for gastric cancer and colorectal cancer were studied. Tissue NCS concentration of proximal lymph nodes were higher than for distant lymph nodes, while the immunocompetency of distant lymph nodes (lower NCS concentration) showed slightly higher activity than that of proximal lymph nodes. From these results, it is suggested that loco-regional administration of NCS might be effective for chemical lymph node cleaning of the cancer.

Carbon↗
PubMed1994

A cellular protein which is coprecipitated with HTLV-I rex protein in the presence of the target mRNA.

We examined the cellular protein(s) which can associate with Rex protein of human T cell leukemia virus type I (HTLV-I), using Rex-maltose binding protein (MBP) fusion protein. Immunoprecipitation of RexMBP with anti-MBP antibody revealed that a 24 kD protein (p24) associated with RexMBP only in the presence of Rex-responsive mRNA. The fact that p24 was present in both the nucleus and the cytoplasm is consistent with a role of Rex in the nucleo-cytoplasmic transport of viral mRNAs. P24 did not interact with nonfunctional Rex mutant proteins even if they had RNA binding activity in vitro. These results suggest the possible involvement of p24 in the Rex function through a complex formation with Rex on Rex-responsive mRNA.

Amino Acid Sequence↗
PubMed1994

[Surgical removal of right atrial myxoma in the elderly].

We have experienced a surgical treatment of right atrial myxoma in a 76-year-old woman. The patient was admitted with complaints of palpitation and low grade fever. Echocardiography revealed the atrial tumor, which prolapsed into the right ventricle in diastole. The tumor was removed under cardiopulmonary bypass including the atrial septum where it was attached. The tumor weighed 68 g and showed typical pathological findings of myxoma. The patient is doing well 6 years after surgery.

Aged↗
PubMed1993

Chemical structure of the 2-keto-3-deoxyoctonate region of lipopolysaccharide isolated from Porphyromonas (Bacteroides) gingivalis.

Structural analysis of the 2-keto-3-deoxyoctonate region of lipopolysaccharide (LPS) isolated from Porphyromonas (Bacteroides) gingivalis was carried out. The substitution of the polysaccharide portion on the KDO was determined by gas chromatography/mass spectrometry of the product obtained by sequential derivatization of the LPS, including dephosphorylation, permethylation, carboxyl reduction, partial hydrolysis, carbonyl reduction, complete hydrolysis and O-acetylation. It was revealed that the KDO carries the polysaccharide on its position C5 and is phosphorylated on either position C7 or C8, although its exact position is not determined. The structure of the KDO region of P. gingivalis LPS in Gram-negative bacterial LPS had not hitherto been elucidated.

Gas Chromatography-Mass Spectrometry↗
PubMed1993

Fibronectin-binding proteins of a human oral spirochete Treponema denticola.

Major polypeptides from a human oral spirochete Treponema denticola ATCC 33520 were examined to demonstrate their ability to bind to human plasma fibronectin by immunoblot analysis. Of three main polypeptides separated on sodium dodecyl sulfate polyacrylamide gels 53,000-daltons (53-kDa) and 72-kDa surface antigenic proteins and a 38-kDa axial flagellar protein showed the ability to bind to fibronectin, suggesting that fibronectin on host cells can mediate cytoadherence of T. denticola by its binding to the surface proteins or the exposed 38-kDa axial flagellar protein.

Adhesins, Bacterial↗
PubMed1993

Antigenic behaviors of two axial flagellar proteins detected in Treponema denticola.

Two polypeptide antigens with molecular sizes of 34,000 daltons (34 kDa) and 38 kDa were separated from heated cells of a human clinical treponeme strain G7201 and Treponema denticola ATCC 35404, respectively. The rabbit polyclonal antisera against these antigens were produced and examined for their immunological reactions with the two heated antigens or intact spirochetal cells. Immunoblot analysis showed that the 34-kDa protein was also detected in T. denticola ATCC 35404 and ATCC 33520, and the 38-kDa protein was detected only in the two ATCC strains. Immunoelectron microscopy using the two rabbit antisera and protein A-gold complexes demonstrated that the 38-kDa protein antigen was present on the axial flagella of two T. denticola strains, and that the 34-kDa protein was located in the axial flagella of the G7201 cell, but neither in axial flagella nor on outer envelopes of the two ATCC strains cells, suggesting that the native 34-kDa axial flagellar protein of the G7201 strain may be different from that of T. denticola in terms of immunological reactivity.

Antigens, Bacterial↗
PubMed1993

Genetic transformation of Porphyromonas gingivalis by electroporation.

Porphyromonas gingivalis was transformed by electroporation using the DNA of plasmid pE5-2, or its derivative, pYT7. Prior to transformation, pE5-2 was transferred from Escherichia coli to P. gingivalis strains by conjugation (mobilization with R751), and the plasmid DNA was purified from the P. gingivalis transconjugants. Transformation occurred when the recipient strain and the donor strain from which the plasmid DNA was purified were homologous. If they were heterologous, transformation did not take place or did so at a very low frequency. This suggested that a restriction-modification system is present in P. gingivalis strains. Plasmid pYT7 was derived by removing an 8.0 kb AvaI fragment from pE5-2 that was purified from P. gingivalis cells. It has several single-cutting restriction sites such as EcoRI, AvaI and ClaI usable for gene cloning, though it was not stable enough in P. gingivalis cells, probably because the rep gene was derived from a relatively distant species, Bacteroides eggerthii.

Conjugation, Genetic↗