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Biomedical subjects

T Umemoto

Publications and source records attributed to T Umemoto.

At least 19 recordsLinked to original sources
PubMed1997

Clinical study of the relationship between cytological behavior and postoperative prognosis in colorectal cancer cases with special reference to nuclear DNA content and nucleolar organizer regions.

BACKGROUND: We studied the usefulness of nuclear DNA patterns and argyrophylic nucleolar organizer regions (AgNORs) for evaluating the malignant potential of colorectal cancers, which is increasingly being regarded as important in predicting patients' prognosis and for their appropriate postoperative management. METHODS: We measured these two factors in curatively resected specimens of 91 colorectal cancer cases, which were followed up for 1,549 +/- 788 days postoperatively. Ploidy pattern was either diploid or aneuploid, and AgNORs score was either low (LS) or high (HS). Thus, we classified our cases into Group I (diploid, LS). Group II (aneuploid, LS), Group III (diploid, HS), and Group IV (aneuploid, HS). Postoperative survival curves in the cases belonging to these groups were analyzed. RESULTS: Survival rates in Groups I and II were significantly higher than those in Group IV. Correlation between subgroups and clinicopathological factors such as average age, histologic type, depth of invasion, and histologic stage were observed. Incidence of lymph node metastasis at the time of operation and that of postoperative recurrence were higher in group IV than that in groups I and II. CONCLUSIONS: Measurement of DNA ploidy patterns and AgNORs score were found to be useful in evaluating malignant potential of colorectal cancers.

Adult↗
PubMed1997

Treponema medium sp. nov., isolated from human subgingival dental plaque.

A new Treponema species, for which we propose the name Treponema medium, was isolated from subgingival plaque from an adult with periodontal disease. The morphological characteristics, differential biochemical characteristics, and protein profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels of this organism are described. The guanine-plus-cytosine content of the DNA of T. medium is 51 mol%. The levels of DNA-DNA relatedness of the new species to other Treponema species, including Treponema denticola, Treponema vincentii, Treponema socranskii, Treponema pallidum, and Treponema phagedenis, are less than 30%. A phylogenetic analysis based on 16S rRNA sequences distinguished the new Treponema strain from strains belonging to previously described Treponema species. The type strain of T. medium is strain G7201.

Bacterial Proteins↗
PubMed1996

Engraftment of human tumor-infiltrating lymphocytes and the production of anti-tumor antibodies in SCID mice.

We report here the placement of nondisrupted 1-mm3 pieces of fresh human lung tumor biopsy tissue into the subcutis of severe combined immunodeficient (SCID) mice results in the engraftment of tumor-infiltrating leukocytes (TIL) in all but 5 of 148 mice inoculated with 39 different biopsy tissue specimens. In mice coengrafted with tumor and TIL the normal histologic architecture of the tumor and TIL interface was maintained for up to 22 wk. The TIL in the xenograft were shown to divide and were maintained exclusively at the site of tumor inoculation. It is established here that plasma cells in the TIL population produce Abs that react in western blots with tumor cell lysates. These Abs were shown to react with high and low m.w. proteins derived from both the membrane and cytosolic fractions of tumor cell lysates. The production of human Ig was found to be T cell dependent, and immunohistochemistry and in situ hybridization of DNA, using a human-specific cDNA probe, established the human identity of the tumor and TIL. High levels of human Ig in the sera of mice inoculated with tumor biopsy tissue are associated with the growth arrest of adenocarcinoma xenografts. Our results establish the co-engraftment of human tumors and TIL into SCID mice as new animal model with which to evaluate TIL function and novel therapeutic strategies that are designed to augment TIL anti-tumor activity.

Animals↗
PubMed1996

Starch debranching enzyme (R-enzyme or pullulanase) from developing rice endosperm: purification, cDNA and chromosomal localization of the gene.

Starch debranching enzyme (R-enzyme or pullulanase) was purified to homogeneity from developing endosperm of rice (Oryza sativa L. cv. Fujihikari) using a variety of high-performance liquid chromatography columns, and characterized. A cDNA clone encoding the full length of the rice endosperm debranching enzyme was isolated and its nucleotide sequence was determined. The cDNA contains an open reading frame of 2958 bp. The mature debranching enzyme of rice appears to be composed of 912 amino acids with a predicted relative molecular mass (Mr) of 102,069 Da, similar in size to its Mr of about 100,000 Da estimated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The amino acid sequence of rice debranching enzyme is substantially similar to that of bacterial pullulanase, while it bears little similarity to that of bacterial isoamylase or to glycogen debranching enzymes from human muscle and rabbit muscle. Southern blot analyses strongly suggest that the debranching enzyme gene is present as a single copy in the rice genome. Analysis by restriction fragment length polymorphism with a probe including the 3'-untranslated region of cDNA for rice debranching enzyme confirmed that the debranching enzyme gene is located on chromosome 4.

Amino Acid Sequence↗
PubMed1996

Histological findings of human leprosy periapical granulomas.

Histological analysis of human leprosy periapical granulomas was conducted to study the histological responses to Mycobacterium leprae. Many Langhans-type giant cells and epithelioid cell tubercles were observed, although M. leprae were not detected in leprosy periapical granulomas. Although numerous T- and B-cells were infiltrated in leprosy periapical granuloma, the T-/B-cell ratio of leprosy is not changed to that of periapical granulomas isolated from normal patients. These findings suggested that human leprosy periapical granulomas develop as a result of immunological responses to M. leprae.

B-Lymphocytes↗
PubMed1996

Immunological studies on venereal spirochetosis of rabbits (rabbit syphilis).

White rabbits in a family, which were clinically diagnosed as moderately or severely diseased with spirochetosis, were bacteriologically and immunologically examined. The specimens from the diseased rabbits, including affected prepuces, scrotum, or skins with an occasional presence of the spirochetes, did not, however, result in growth in six conventional culture media. Serological tests, including quantitative complement fixation test, rapid plasma reagin card test, Treponema pallidum hemagglutination test, and microscopic agglutination test for leptospires using sera from diseased rabbits showed no differences when compared with those of pooled normal rabbit sera. Immunoblot analysis of the polypeptides from three human oral treponemes and three non-oral spirochetes demonstrated that antibodies against several treponemal polypeptides were detected.

Animals↗
PubMed1996

Growth inhibition of a human oral bacterium Porphyromonas gingivalis by rat cysteine proteinase inhibitor cystatin S.

Agar diffusion analysis demonstrated that rat cystatin S, a cysteine proteinase inhibitor, inhibited the growth of all tested strains of a human oral, Gram-negative anaerobic periodontopathogen Porphyromonas gingivalis. Its specific inhibitory activity against this tissue-invasive bacterium but not against other tested oral bacterial species emphasized the importance of specific cysteine proteinases for growth of P. gingivalis.

Animals↗
PubMed1996

Porphyromonas gingivalis fimbrillin is one of the fibronectin-binding proteins.

In this study, we demonstrate that Porphyromonas gingivalis fimbrillin, a major component of bacterial fimbriae, is one of the fibronectin-binding proteins and that fibronectin is a potent inhibitor of the adherence of the bacteria to host cells and of the pathogenesis of the bacterium that acts by binding to the fimbriae. A Western blotting (immunoblotting) assay showed that fibronectin binds strongly to P. gingivalis fimbrillin. The fimbrial binding to fibronectin was also evidenced by a binding assay involving 125I-labeled fimbriae. Furthermore, fibronectin markedly inhibited the fimbria-induced expression of interleukin-1beta and neutrophil-specific chemoattractant KC genes in macrophages. The inhibitory action depended on the fimbrial interaction with heparin-binding and cell attachment domains in the fibronectin structure. The binding of P.gingivalis to mouse peritoneal macrophages via its fimbriae was inhibited by fibronectin. Fibronectin also inhibited the bacterial cell-induced expression of interleukin-1beta and KC genes in the macrophages. These results demonstrate the importance of fibronectin as a modulator of the pathogenic mechanism of P. gingivalis, a pathogen that causes adult periodontal disease.

Adhesins, Bacterial↗
PubMed1996

Atomic force microscopy in histology and cytology.

This review briefly introduces the principles of the atomic force microscope (AFM) and shows our own results of AFM application to biological samples. The AFM, invented in 1986, is an instrument that traces the surface topography of the sample with a sharp probe while monitoring the interaction forces working between the probe and sample surface. Thus, the AFM provides three-dimensional surface images of the sample with high resolution. The advantage of the AFM for biologists is that AFM can visualize non-conductive materials in a non-vacuous (i.e., air or liquid) environment. AFM images of the plasmid DNA are comparable to those by transmission electron microscopy using a rotary shadowing technique, and have the advantage of examining directly the molecule without staining nor coating. The surface structure of human metaphase chromosomes and mouse collagen fibrils demonstrated in air by the non-contact mode AFM is comparable to that obtained by scanning electron microscopy. Quantitative information on the heights of structures is further obtainable from the AFM images. Embedment-free thin tissue-sections are useful for observing intracellular structures by AFM. The present review also shows AFM images of living cultured cells which have been collected in a contact mode in liquid. This technique afforded us three-dimensional observation of the cellular movement with high resolution. Although there are some innate limitations for AFM imaging, the AFM has great potential for providing valuable new information in histology and cytology.

Animals↗
PubMed1996

[Locoregional therapy for liver metastases of colorectal cancer].

The role of biological response modifiers (BRM) in locoregional therapy for liver metastases of colorectal cancer was studied clinically and experimentally. Seven patients with numerous metastases to both lobes of liver were given intraarterial administration of BRM in combination with anticancer drugs. A partial response was observed in 1 patient. The response rate was 14.3%. Alternatively, intraarterial administration of both OK-432 and IL-2 into the rabbit with liver metastases of VX-2 tumors could bring about the infiltration of cytotoxic T lymphocytes around the tumors, followed by a significant decrease of the metastatic nodules. In addition, the same anti-tumor effect was observed when PSK was administered intraperitoneally into the BALB/c mouse with liver metastases of colon 26 tumors. Moreover, the therapeutic effect of water in oil type emulsion encapsulating both OK-432 and IL-2 was greater than that of the solution of BRM in BALB/c mouse with liver metastases of colon 26 tumors. These results indicated that BRM could be one of the promising agents in locoregional therapy against liver metastases of colorectal cancer.

Adult↗
PubMed1996

[A case report of multiple pseudoaneurysms of the left ventricle following acute myocardial infarction].

Multiple pseudoaneurysms of the left ventricle following acute myocardial infarction were successfully repaired in a 50-year-old man. Three days after onset of acute myocardial infarction, we electively performed PTCA on the right coronary artery which was completely occluded at the proximal segment. One month after PTCA, the left ventriculogram revealed multiple pseudoaneurysms of the left ventricle. Primary closure of orifices of the pseudoaneurysms was performed using pledgeted mattress sutures under cardiopulmonary bypass. Histology of aneurysm confirmed the diagnosis of pseudoaneurysm.

Aneurysm, False↗
PubMed1995

Immunological characterization and localization of a Porphyromonas gingivalis BApNA-hydrolyzing protease possessing hemagglutinating activity.

A monoclonal antibody (mAb-PC) was produced against a BA pNA-hydrolyzing protease possessing hemagglutinating activity (Pase-C) from Porphyromonas gingivalis. Other P. gingivalis BA pNA-hydrolyzing enzymes (Pase-B and Pase-S) did not react with this antibody. By ELISA or SDS-PAGE and Western immunoblotting analysis, mAb-PC recognized all P. gingivalis and P. endodontalis strains tested but did not recognize other members of the Porphyromonas genus nor other putative periodontopathogenic organisms. Pase-C, extracellular vesicles (ECV) and human strains of P. gingivalis showed two major immunoreactive bands (44 kDa and 40 kDa), whereas a different pattern was obtained with animal strains of P. gingivalis. Biotinylarginyl chloromethane, an irreversible inhibitor of trypsin-like proteases, did not affect the reactivity of Pase-C with mAb-PC on immunoblot. By reversed-phase electronmicroscopy following immunogold labeling, the antibody was shown to bind to the cell surface of P. gingivalis. mAb-PC inhibited the hemagglutinating activity of both P. gingivalis cells and ECV whereas a monoclonal antibody against LPS of P. gingivalis did not. These results suggest that Pase-C is located on the cell surface of P. gingivalis and may participate in erythrocyte binding.

Animals↗
PubMed1995

Development of near-field optic/atomic force microscope for biological materials in aqueous solutions.

This paper reports improvements of optical fiber cantilevers and the scanning near-field optical microscopy imaging of biological materials in liquid. In our scanning near-field optical/atomic-force microscope (SNOAM), the scanning of an optical fiber cantilever over the specimen was controlled by dynamic mode AFM to reduce damage to the probe and soft specimens. The typical resonant frequency of the optical fiber cantilever was 19.5 kHz, while it was 23.0 kHz in air. The Q-factor of the cantilever depended on the vibration amplitude and was typically 260-600 in air and 40-240 in water. The relationship between the vibration amplitude and the average sample-probe separation indicated that the cantilever worked in the non-contact mode in water, while it worked in the cyclic-contact mode in air. Cultured cells in aqueous solutions were visualized by the SNOAM, indicating that the SNOAM is suitable to observe soft specimens.

Animals↗
PubMed1995

Bactericidal effect of rat cystatin S on an oral bacterium Porphyromonas gingivalis.

We tested antibacterial and antiviral activities of rat cystatin S, a cysteine proteinase inhibitor, belonging to the family 2 cystatins against 18 different bacterial species and poliovirus type 1 (Sabin). Rat cystatin S specifically inhibited the growth of a human oral anaerobic bacterium Porphyromonas gingivalis due to a bactericidal effect.

Amino Acid Sequence↗
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↗