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T Tanigawa

Publications and source records attributed to T Tanigawa.

At least 109 records · Page 6Linked to original sources
PubMed1995

Mutual contact of adherent polymorphonuclear leukocytes inhibits their generation of superoxide.

Superoxide generation by polymorphonuclear leukocytes (PMNs) in suspension, or adherent to glass or plastic, after stimulation with N-formylmethionyl-leucyl-phenylalanine or phorbol myristate acetate was measured by cytochrome c reduction and spin trapping. Amounts of superoxide generated by adherent PMNs were inversely related to cell density. The generation of hydrogen peroxide was also inhibited at higher cell densities. In contrast to adherent cells, superoxide released by PMNs in suspension linearly increased with respect to cell number over a wider range. Microscopic observation indicated that the number of cells in mutual contact increased rapidly at cell densities higher than 4 x 10(4) cells/cm2, and inhibition of superoxide became apparent at higher cell densities. Mediators which could be released by PMNs, such as NO and adenosine, were not the cause of inhibition. These data suggest that mutual contact of PMNs suppresses their generation of superoxide. Survival rates of PMNs after stimulation increased at higher densities, indicating that the mutual contact-induced inhibition of superoxide generation by PMNs may be physiologically relevant at sites of inflammation.

Cell Adhesion↗
PubMed1995

[Effects of kanamycin on platelet satellitism and leukocyte adhesion phenomena].

To examine the effects of kanamycin on platelet satellitism and leukocyte adhesion phenomena, we added kanamycin to the blood sample which showed the platelet satellitism and the leukocyte adhesion phenomena. We observed the rapid dispersion of platelets from the surface of leukocyte in platelet satellitism and also the rapid dispersion of leukocyte in leukocyte adhesion by addition of kanamycin (20 mg) in 1 ml of EDTA-anticoagulated blood from a patient with both phenomena. Neither adhesion of platelet nor adhesion of leukocyte was found on microscopical examinations after dispersion. Complete blood cell counts and their histogram patterns after dispersion were almost the same as those just after venipuncture. The dispersion was found just after the addition of kanamycin and no re-adhesion was observed. These findings suggest that kanamycin leads to dispersions of leukocyte-leukocyte, platelet-platelet and leukocyte-platelet adhesion phenomena.

Cell Adhesion↗
PubMed1994

Spin trapping of superoxide in aqueous solutions of fresh and aged cigarette smoke.

Superoxide generation in aqueous solutions of cigarette smoke was determined as a function of the age of smoke using spin trapping. As a spin trap, 5,5-dimethylpyrroline-N-oxide (DMPO) was used. The superoxide adduct of DMPO was detected in a solution of fresh main-stream smoke for over 1 h. The superoxide-generating potential of smoke was rapidly lost as the smoke was kept in a plastic syringe. The smoke that was aged for 3 min did not generate superoxide. Additional evidence of superoxide generation in aqueous solutions of cigarette smoke was obtained by the chemiluminescence method.

Cyclic N-Oxides↗
PubMed1994

Determination of the rate of superoxide generation from biological systems by spin trapping: use of rapid oxygen depletion to measure the decay rate of spin adducts.

A method was developed to measure the superoxide generation rate from biological systems using the spin trapping method. Kinetic treatment of the decay rate of the superoxide adduct of 5,5-dimethylpyrroline N-oxide (DMPO) revealed that the EPR signal intensity of the system is proportional to the superoxide generation rate. Rapid depletion of oxygen in the sample was utilized to terminate superoxide generation so that the decay rate of the DMPO superoxide adduct (DMPO-OOH) could be determined. For this decay measurement, a controlled atmosphere EPR cavity was developed and was used with an open-air sample cell. Superoxide generation rates determined with this method for stimulated neutrophils and for the hypoxanthine-xanthine oxidase system were comparable to those obtained with the cytochrome c reduction method. This method is specifically applicable to the system in which dissolved oxygen supplied from the gas phase is utilized as a source of superoxide.

Cyclic N-Oxides↗
PubMed1994

Interferon as adjunctive treatment for non-metastatic renal cell carcinoma.

OBJECTIVE: To investigate the effect of recombinant alpha 2b-interferon therapy on natural killer (NK) activity and antibody-dependent cell-mediated cytotoxicity (ADCC) in the peripheral blood in patients with renal cell carcinoma who had undergone radical nephrectomy. PATIENTS AND METHODS: Between January 1988 and June 1989, 20 patients (14 men and six women, mean age 59 years, range 43-80) received interferon (IFN) therapy following radical nephrectomy for renal cell carcinoma. Thirteen patients had stage I disease, one had stage II and six had stage III; none had metastases. RESULTS: There was a significant increase in NK activity at 5 and 7 months after starting IFN therapy but there was no increase in ADCC. CONCLUSIONS: Low doses of IFN administered long-term increased NK activity in patients with renal cell carcinoma. This finding should be helpful in designating protocols for randomized studies of post-operative IFN administration as adjuvant therapy.

Adult↗
PubMed1994

Antioxidative effects of a processed grain food.

Antioxidant biofactor: AOB is a unique processed grain food. It is a yellow-green powder. It contains the following extracts: germ extracts, soybean, rice bran, tear grass, sesame, wheat, citron, green tea, green leaf extract, and malted rice. These materials were slowly roasted under a powdered oure at less than 60 degrees C and fermented with Aspergillus oryzae over 3 days to transform each ingredient into low molecular weight substances. These conditions were different by each material, environmental humidity and temperature. It probably contains a variety of substances having antioxidant activity including flavonoids, alpha-tocopherol, vitamin C, and tannins. We investigated its antioxidative properties using electron spin resonance (ESR) and autoxidation of rat brain homogenates. The superoxide, hydroxyl radical, and the stable free radical, diphenyl-p-picrylhydrazyl (DPPH) radical scavenging activity of AOB was investigated using ESR spectrometry. In an in vitro study, a suspension of AOB was added directly to a superoxide generating system (hypoxanthine-xanthine oxidase; HX/XO) and investigated using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trapping agent. At final concentrations of 0.01, 0.05, and 0.1 mg/ml, AOB dose-dependent scavenging activity was observed as 0.103, 0.619, and 1.369 U/ml, respectively. A concentration of 1.0 mg/ml completely scavenged DMPO-OOH signals; 1.0 mg/ml of AOB inhibited the DMPO-OH signal generated by Fenton's reaction, but its inhibitory effect was not competitive, and was inhibition of the Fenton's reaction. 1.0, 3.0, and 5.0 mg/ml of AOB were significantly inhibited the DPPH radical. In an in vivo study, rats were fed AOB orally at doses of 1 or 5 g/day for 24 h or for 3 days and the superoxide scavenging activity was measured in plasma. With the administration of 1 g/day for 3 days, the superoxide scavenging activity was about 1.8 times that of the control group fed a basal diet; 1.5 times the control with 5 g/day for 1 day, and 2.6 times the control with 5 g/day for 3 days, all of which represented significant increases in superoxide scavenging activity. AOB strongly inhibited the autoxidation of rat brain homogenates in vitro in a dose-dependent manner. However, each ingredient before roast and fermentation little inhibited lipid peroxidation. Roasting and fermentation with A. oryzae way be important to transform each ingredient into low molecular weight substances. Therefore, it was suggested that AOB possesses strong antioxidant and free radical scavenging activities.

Animals↗
PubMed1994

[Quantitation of HTLV-I proviral copies of infected cells in pregnant HTLV-I carriers and its correlation with vertical infection].

Using colony formation in poly-L-lysine chamber slides and the polymerase chain reaction (PCR), we quantitated the number of human T lymphotropic virus type-I (HTLV-I) infected cells and proviral copies in peripheral blood lymphocytes from 25 pregnant HTLV-I carriers. The number of HTLV-I proviral copies in 0.25 microgram of DNA ranged from 2.8 to 9,176, with approximately 1-40 HTLV-I proviral copies per infected cell. The number of HTLV-I proviral copies was correlated with the number of infected cells in PBL. The HTLV-I antibody level was not correlated with the number of HTLV-I proviral copies per infected cell. By comparing the HTLV-I antigen positivity rate in another 31 HTLV-I carriers who were fed breast milk, we found that the risk of vertical infection might be high at more than 9.4 copies per infected cell. Multiple proviral copies may therefore exist in 1 HTLV-I infected cell and the number of HTLV-I proviral copies per infected cell is an important factor in vertical infection.

Carrier State↗
PubMed1994

Constitutive expression of the putative transcription factor SCL associated with proviral insertion in the myeloid leukemic cell line WEHI-3BD-.

The murine myeloid leukemia WEHI-3B contains an intracisternal A-particle insertion in a growth factor gene (IL-3) and a homeobox gene (Hox 2.4). Southern blot analysis of the differentiation unresponsive subline WEHI-3BD- demonstrated a rearrangement of the SCL gene, a gene that encodes a protein of the helix-loop-helix class of transcription factors. Northern blot analysis demonstrated an abnormal SCL transcript in the WEHI-3BD- cells, although SCL expression was not detected in the parental cells. The rearrangement was cloned and confirmed as an insertion of an intracisternal A-particle in the 3' untranslated region of the SCL gene. Although SCL is implicated in up to 25% of human T-cell acute lymphoblastic leukemia, this is the first example of SCL involvement in a myeloid leukemia.

Animals↗
PubMed1993

Enzyme release assay of human NK cell activity using beta-galactosidase-expressing K562 target cell line.

In the present report, we established a K562 cell line useful for an enzyme release assay of human natural killer (NK) activity. Human myelogenous leukemia cell line, K562, was transfected with a plasmid carrying Escherichia coli beta-galactosidase (beta-gal) gene. A colony that permanently expresses the enzyme activity was isolated, and designated K562/Zneo. Incubation of K562/Zneo cells (1 x 10(4)) with nonadherent human peripheral blood lymphocytes (PBL) resulted in the release of beta-gal activity depending on the incubation time and the number of effector cells. Released beta-gal activity was assayed sensitively by using 4-methylumbelliferyl-beta-D-galactoside, a fluorescent substrate. The cytolytic activity of PBL was augmented significantly when the cells were preincubated with interleukin-2 for 20 h. This enzyme release assay showed a comparable sensitivity to that of 51Cr release assay. Thus, K562/Zneo cell line is thought to be useful for the nonradioactive assay of human NK and lymphokine-activated killer activities.

Cytotoxicity, Immunologic↗
PubMed1993

The SCL gene product is regulated by and differentially regulates cytokine responses during myeloid leukemic cell differentiation.

Differentiation induction in murine M1 leukemia cells by interleukin 6 (IL-6), leukemia inhibitory factor (LIF), and oncostatin M (OSM) is postulated to occur via a common receptor chain, gp130. In this study, growth factor-induced differentiation of M1 cells was accompanied by a late and persistent decrease in levels of mRNA and protein for a helix-loop-helix transcription factor, the SCL gene product. To evaluate whether reduced SCL expression was instrumental in monocyte differentiation, an SCL cDNA expression vector was introduced into M1 cells to obtain cell lines in which overexpression of SCL mRNA and protein was enforced. This resulted in a reduction in cells differentiating in response to LIF and OSM but not in response to IL-6. Scatchard analysis indicated that both parental and SCL-transfected cell lines exhibited similar receptor numbers and receptor affinities for LIF, OSM, and IL-6, suggesting that the differential responsiveness was not due to selective receptor down-modulation. Thus, these data implicate SCL in monocytic differentiation and provide evidence for differential receptor signaling pathways despite utilization of a common gp130 subunit by all three receptors.

Animals↗
PubMed1993

Family study of women showing development of antibody to human T-cell leukemia virus I and assessment of the risk of vertical transmission of the virus to their children.

When pregnant women were tested for antibody to human T-cell leukemia virus-I, some were found to be positive although they had been negative during the previous pregnancy. In these women, HTLV-I infection was found from pedigree studies to have been acquired from their mothers rather than from their husbands. Furthermore, some of them had apparently remained HTLV-I antibody-negative for long periods after infection. When the breast-fed children of these women, in whom HTLV-I was acquired from their mothers but who were in an HTLV-I antibody-negative state, were also examined for evidence of HTLV-I infection, none was found.

Carrier State↗
PubMed1993

Spin trapping of superoxide radicals following stimulation of neutrophils with fMLP is temperature dependent.

Oxygen radical formation by human neutrophils stimulated with a chemotactic peptide, formyl-methionyl-leucyl-phenylalanine (fMLP), was studied through the use of spin trapping and superoxide dismutase-inhibitable reduction of oxidized cytochrome c. Both methods provided comparable data on temperature-dependent kinetics of superoxide radical formation, but hydroxyl radicals were also detected in spin-trapping experiments. When superoxide generation was monitored at 37 degrees C, the respiratory burst lasted only a few minutes. If the neutrophils were stimulated at 37 degrees C, but superoxide measurements were done at room temperature, the respiratory burst was again transient. However, neutrophils persistently generated superoxide when both stimulation and subsequent measurements were performed at room temperature. In the presence of the actin polymerization inhibitor, cytochalasin B, superoxide generation was persistent, even when measurements were conducted at 37 degrees C. A possible explanation for these observations is that the fMLP receptor complexes quickly aggregate and are internalized at physiological temperature, but not at room temperature. Very little superoxide was formed if cells were kept at a temperature of 4 degrees C for 1 h prior to fMLP addition, which is consistent with decreased expression of the fMLP receptor at cold temperatures.

Cytochalasin B↗