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Biomedical subjects

T Umemoto

Publications and source records attributed to T Umemoto.

At least 127 records · Page 7Linked to original sources
PubMed1986

[Cytotoxicity of interleukin 2-induced lymphocytes and effects of serum immunosuppressive factors].

IL2-induced lymphocytes (IIL) obtained from normal subjects were examined as to a possibility for induction of tumor-specific killer cells. Moreover, effects of serum on their cytotoxic activity were observed. The IIL which were pre-sensitized with mitomycin C-treated MKN-28 (IILM), showed a markedly increased cytotoxic activity against MKN-28. The IIL which were either pre-cultured with PHA or not, showed augmentation of cytotoxic activity against various human cancer cell lines, although their cytotoxic activity against MKN-28 was lower than that of IILM. The cytotoxic activity of IILM was suppressed by addition to the medium of non-specific immunosuppressive factors (IAP, ferritin, alpha-fetoprotein) or of various sera obtained from gastric cancer patients, in whom histological diagnosis was tub1, por or sig, but the suppression to the IILM activity was significantly milder than that to the activity of peripheral lymphocytes. The degree of suppression by tub1 serum was significantly higher than that by the serum from por or sig. When tub1 serum was added to the medium during pre-sensitization, the cytotoxic activity of IILM against MKN-28 was reduced significantly. However, addition of por or sig serum showed no significant reduction in cytotoxic activity of IILM.

Adenocarcinoma↗
PubMed1985

Antitumor effect in peritoneal carcinomatosis of intraperitoneal administration of a streptococcal preparation, OK-432: I. Experimental study in the rat.

The effect of intraperitoneal OK-432 administration and its mechanism of action were investigated using an experimental rat tumor. On day 4 or 6 of intraperitoneal inoculation of tumor cells, 50 Klinische Einheit (KE)/kg of OK-432 was intraperitoneally administered, and intraperitoneal exudate cells were microscopically examined daily. Distribution of peritoneal exudate cells: A marked increase in neutrophils was noted in ascites at 24 hours after intraperitoneal administration of OK-432, with macrophages and lymphocytes appearing later than neutrophils. A subsequent decrease in neutrophils was accompanied by a gradual increase in tumor cells. Findings of tumor cells: When OK-432 was intraperitoneally administered on day 4 of tumor inoculation, aggregation of neutrophils around tumor cells was observed on day 6, and rosette formations around tumor cells were noted on day 7 or 8. Subsequently tumor cells that formed the centers of the rosettes were destroyed and disappeared. These reactions were not observed when OK-432 was administered on day 6, nor were they observed in untreated cases. These results suggest that cytotoxic effects of intraperitoneally administered OK-432 were displayed mainly by rosette formation by neutrophilic cells, as far as this model was concerned.

Animals↗
PubMed1985

Characterization and mode of action of a purified bacteriocin from the oral bacterium Streptococcus mutans RM-10.

The purified bacteriocin was sensitive to proteolytic enzymes such as trypsin, alpha-chymotrypsin and pronase, but resistant to papain and pepsin. Lowering the pH of the bacteriocin caused precipitation, and the Abs280 of the supernatant reached a minimum at pH 3.6, suggesting that this is the isoelectric point. Such a pH value coincides with minimum bacteriocin activity. The effect of the bacteriocin was bactericidal rather than bacteriolytic and concentration dependent. Treatment of Streptococcus faecalis ODU with Rm-10 bacteriocin led rapidly to the cessation of biosynthesis of macromolecules, DNA, RNA and protein. Electron microscopy showed bacteriocin fibres attached in aggregated bundles to target cells; after ultra-sonication or detergent treatment they were individually attached to the cell surface and, at the same time, the apparent bacteriocin activity had doubled. Bacteriocin activity was not altered by filter-sterilized saliva components. Oral rinsing with Rm-10 bacteriocin reduced the number of viable salivary bacteria after 20 min, suggesting a possible therapeutic use for Rm-10 bacteriocin.

Animals↗
PubMed1985

[Clinical study on serum immunosuppressive factors in gastric cancer patients--with special reference to preoperative IAP values and the influence of surgical stress].

Serum IAP values were measured preoperatively in 83 gastric cancer patients. The levels were significantly higher in cases of total, stage III and IV, n (+) and non-curative resection than in normal subjects, stage I, n (-) and curative resection. There was a significant correlation between IAP on the one hand, and IgG FcR (+) T cell, alpha 2-globulin and CEA on the other. OK-432 was serially administered pre- and postoperatively (A) and only postoperatively (B). IAP was examined at one, two and four weeks postoperatively, and the findings were compared. It was increased markedly at one week and was slightly reduced at two and four weeks. These changes in IAP showed no significant differences between groups A and B.

Carcinoembryonic Antigen↗
PubMed1985

[Relations of tumor-specific cytotoxicity to nonspecific immunological parameters and to clinical course in various surgical cancer patients].

Human malignant cells, obtained from surgical specimens or pleuro-peritoneal exudate in 105 cases, were cultivated. Tumor-specific immunity was estimated by cytotoxicity assay using mixed autologous lymphocyte-tumor cell culture in 27 cases (40 times in all). Relations of the observed specific immunity to various nonspecific immunological parameters and to clinical responses to immunotherapy were examined. Positive reaction was observed in 14 examinations. Eight of 25 digestive tract cancers and 6 of 15 other cancers were positive. Cytotoxic activity was significantly higher in the group of favorable clinical response than in the group of progressive disease. In the group of positive cytotoxicity, incidence of clinical response was significantly higher than in the group of negative cytotoxicity. A significant positive correlation was found between cytotoxicity and T cell ratio. Incidence of positive cytotoxicity tended to be higher in the cases of single OK-432 administration (6/11). Incidence of clinical response was higher in the cases of combined OK-432 and PSK administration group (4/14). In the positive cytotoxicity group, 3 examinations showed progressive disease and 5 showed no change. It has been suggested that a higher incidence of favorable clinical response is to be expected in case of positive cytotoxicity, if some therapy will be combined with the conventional immunotherapy.

Adjuvants, Immunologic↗
PubMed1985

[Serum lipids and lipoproteins in peripheral vascular disease].

Serum lipids and lipoproteins were investigated in 102 cases with arteriosclerosis obliterans (ASO), 41 cases with Buerger's disease (TAO) and 133 normal controls. The following results were obtained. In ASO, triglyceride, beta-lipoprotein, free fatty acid were higher than control, but total cholesterol and lipid peroxide were not increased. LDL and VLDL increased though LCAT decreased in ASO. ASO had lower HDL-cholesterol, HDL-phospholipid and apoprotein-A levels than control. HDL-cholesterol/HDL-phospholipid and HDL-cholesterol/Apoprotein-A ratios decreased also, indicating changes in quality in addition to quantity. In young patients with ASO, total cholesterol and LDL were higher than in old one. The same tendency was found in patients with proximal occlusion (aorto-iliac). In TAO, triglyceride, free fatty acid and VLDL increased and HDL-cholesterol, Apoprotein-A and LCAT decreased than that of control. These data may suggest that the change of lipids and lipoproteins in ASO are same in coronary heart disease.

Adult↗
PubMed1984

Colonial morphology of treponemes observed by electron microscopy.

The colonial morphology of three strains of cultivable, nonpathogenic treponemes including a human oral treponeme was examined by light and electron microscopy. Treponema phagedenis strains Kazan and Reiter produced large white colonies on the surface of solid media composed of sterility test broth, 0.9 to 3.1% agar, rifampin, and 12.5% rabbit or horse serum. A human oral treponeme, strain G7201 , grew as diffused white zones on 0.9 to 3.1% agar plates. Under the cultural conditions employed agar concentrations slightly affected the time of appearance of colonies of the three strains of treponemes. When the colonies of these three strains were viewed by scanning electron microscopy, differences in their colonial morphology were observed. The 11-day-old colonies of human oral strain G7201 were very small, 5 to 15 micron in diameter, and had a slight irregular border. Kazan treponemes developed circular, entire and low convex colonies. Scanning and transmission electron microscopy revealed that the colonies of Reiter treponemes contained spherical forms almost up to 5 micron in diameter, each consisting of an outer membrane and a treponemal main body. They were very similar to the spherical bodies produced by strain G7201 in sucrose-containing broth.

Agar↗
PubMed1984

[Clinical studies on preoperative nonspecific immunological parameters and radical operation in stomach cancer].

Ratio of IgG Fc receptor positive T (Fc R(+) T) cell, PHA-induced blastogenesis and serum alpha 2-globulin ratio were examined in 90 preoperative cases with gastric cancer and were analyzed according to various stages of cancer and compared with normal controls. Moreover, on the basis of correlations among these parameters, operative radicality and prognosis were discussed. Fc R(+) T cell ratio was significantly elevated. PHA- blastogenesis was significantly reduced. Alpha 2-globulin ratio tended to increase as the stage progressed. A significant negative correlation was found between Fc R(+) T cell ratio and PHA- blastogenesis. In a scattergram indicating this correlation, the group of noncurative resection or exploratory laparotomy was divided into two areas, B1 and B2. The group of curative resection (A1) was located between B1 and B2, and the normal control group was located in the area common to B1 and A1, Cases succumbing to cancer within one year postoperatively were found to accumulate either in the area B2 or in the area B1 minus the area common with A1. No significant correlation was found between Fc R(+) T cell ratio and alpha 2-globulin ratio. However in a scatter gram, the almost same relationship between these three groups was noted. Thus it has suggested that postoperative prognosis (at least for two years) is good in cases which an immunological harmony among these parameters is maintained preoperatively.

Adult↗
PubMed1983

Isolation, partial purification and preliminary characterization of a bacteriocin from Streptococcus mutans Rm-10.

An extracellular bactericidal substance was isolated from the supernatant of Streptococcus mutans Rm-10 culture fluid and partially purified with 60% ammonium sulfate precipitation, differential centrifugation, and gel filtration on Sephadex G-200. There was a good correlation of the sensitivity profiles of indicator strains whether assayed on solid medium or with purified material from cell-free culture fluid, indicating that the same inhibitory substance is produced on solid medium and in broth. Vapor from organic solvents such as chloroform, acetone, ethanol, and ether as well as heat treatment at 100 degrees C for 30 min had little effect on the bactericidal factor. It was sensitive to trypsin and pronase and resistant to deoxyribonuclease, ribonuclease, lysozyme, and phospholipase C. The inhibitor was not infective, and electron microscopic studies failed to reveal phage or phage-like particles in concentrated solutions of the bactericidal material. The results indicate that the extracellular bactericidal substance is indeed a bacteriocin. Activity in broth cultures reached a maximum only after exponential growth had ceased. It was active against other streptococcal strains as well as strains of Actinomyces naeslundii, A. viscosus, Bacillus subtilis and Staphylococcus aureus, but not against strains of Fusobacterium nucleatum and Escherichia coli.

Actinomyces↗
PubMed1983

Purification and quantitative chemical analysis of cell wall peptidoglycans of Leptotrichia buccalis.

Peptidoglycans of Leptotrichia buccalis ATCC 14201 and ATCC 19616 were isolated by extraction with sodium dodecyl sulfate and subsequent digestion of the sodium dodecyl sulfate-insoluble residue with proteases and alpha-amylase. Cell wall fractions obtained by sodium dodecyl sulfate extraction and protease digestion were highly contaminated by a glucose polymer. The polyglucose was removed by alpha-amylase treatment, and the peptidoglycans were left behind. Analyses with amino acids and amino sugars of the cell wall fractions and peptidoglycan specimens revealed that D-glutamic acid, D-alanine, L-alanine, meso-2,6-diaminopimelic acid (A2pm), muramic acid, and glucosamine were the principal components. The dinitrophenylation method revealed that about half of the A2pm residue had a free amino group, and analysis by hydrazinolysis showed that a small part of alanine and A2pm was located at the C terminal. The above results indicate that one of the amino groups of the A2pm residue at one strand of the stem peptide subunit cross-linked to the carboxyl group of alanine of the neighboring strand. It was thus revealed that the peptidoglycans of L. buccalis belong to the A1 gamma type of the classification by Schleifer and Kandler (Bacteriol. Rev. 36:407-477).

Amino Acids↗
PubMed1982

An internal view of the spherical body of Treponema macrodentium as revealed by scanning electron microscopy.

The osmium-dimethyl sulfoxide-osmium method for clear visualization of intracellular structure was used to observe the detailed inner structure of the spherical bodies produced in vitro by a human oral treponeme. Scanning electron microscopy of the cracked spherical body revealed no morphological differences between the outer and inner surfaces of the spherical body membrane, and that multiple folded or somewhat linear main bodies adhere closely to the inner surface. In addition, axial flagella partially free from the main bodies spread widely within the body to make a network, and a number of blebs ranging from approximately 1 micrometer to 0.2 micrometer in diameter were located near the terminal or subterminal areas of the main bodies. The origin of the blebs and the mechanism of spherical body formation are discussed.

Microscopy, Electron, Scanning↗