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1.
Localization of cytochrome P-450 in the colonic mucosa of 3-methylcholanthrene-pretreated and untreated rats An immunohistochemical study 总被引:1,自引:0,他引:1
Dr. Shinji Tamura Sumio Kawata Mitsuhiro Okamoto Seiichiro Tarui 《Cell and tissue research》1988,252(2):397-401
Summary Immunohistochemical localization of cytochrome P-450 in the colonic mucosa of 3-methylcholanthrene-pretreated and untreated rats was studied by indirect fluorescent antibody staining technique. A polyclonal antibody for cytochrome P-450MC purified from hepatic microsomes of 3-methylcholanthrene-pretreated rats was used for this experiment. A strong immunofluorescence was found to be localized in the cytoplasm of the surface epithelium of the mucosa in the colon of 3-methylcholanthrene-pretreated rats. A faint immunofluorescence was also observed in the epithelium of untreated rats. 7-Ethoxycoumarin O-deethylase activity of colonic microsomes was significantly enhanced by 3-methylcholanthrene-pretreatment in parallel with an increase in the intensity of immunostaining for cytochrome P-450MC in Western blotting analysis. This is the first report on the localization of cytochrome P-450 in the colonic mucosa. 相似文献
2.
Summary The rnh gene of Escherichia coli encodes RNase H. rnh mutants display at least two phenotypes: (1) they require functional RecBCD enzyme for growth; thus rnh-339::cat recB270 (Ts) and rnh-339::cat recC271 (Ts) strains are temperature sensitive for growth; (2) rnh mutants permit replication that is independent of the chromosomal origin, presumably by failing to remove RNA-DNA hybrids from which extra-original replication can be primed. We report here that manifestation of these two phenotypes occurs at different levels of RNase H function; we have examined partially functional rnh mutants for their in vitro RNase H activity, their ability to rescue viability in recB or recC cells and their ability to permit growth of mutants incapable of using oriC [dnaA (Ts)]. 相似文献
3.
Effects of Glyphosate on the Shikimate Pathway and Regulation of Phenylalanine Ammonia-lyase in Cryptomeria and Perilla Cell Suspension Cultures 总被引:1,自引:0,他引:1
Ishikura Nariyuki; Teramoto Susumu; Takeshima Yasunobu; Mitsui Seiji 《Plant & cell physiology》1986,27(4):677-684
Treatment of Cryptomeria and Perilla cell suspension cultureswith glyphosate resulted in a marked suppression of the formationof flavans and caffeic acid derivatives, respectively, whileit caused only a slight decline in the cell growth. In contrastwith 3-deoxy-D-arabino-heptulosonate (DAHP) synthase-Mn isozyme,DAHP synthase-Co isozyme from Cryptomeria and Perilla cellswas much more sensitive to inhibition by glyphosate. The additionof 1 to 2 mM glyphosate caused an accumulation of shikimateand quinate and a reduction of L-phenylalanine in both cellcultures. The inhibition of phenylalanine ammonia-lyase (PAL)activity by glyphosate was reversed by exogenously suppliedL-phenylalanine to near the control level. Cycloheximide andactinomycin D nullified the recovery by exogenous L-phenylalanineon PAL activity. L-Phenylalanine itself promoted PAL activityto some extent. No recovery of PAL activity in L--aminooxy-ß-phenylpropionate(L-AOPP)-treated cell cultures could be observed by the additionof L-phenylalanine. Therefore, L-AOPP seems to inhibit the formationof PAL, though it has been considered a competitive inhibitor.
3Present address: Biological Institute, Faculty of Science,Tohoku University, Sendai 980, Japan. (Received October 28, 1985; Accepted March 13, 1986) 相似文献
4.
5.
Two lines of the red and pale yellow cell suspension cultures, prepared fromPrunus x yedoensis Matsum. callus induced by Murashige and Skoog's (1962) basal medium supplemented with 2, 4-dichlorophenoxyacetic acid (2,
4-D, 1.0 mg/l), kinetin (0.1 mg/l) and sucrose (30 g/l), were maintained on Schenk and Hildebrandt medium as modified by Mitchell
and Gildow (1975). The red cell suspension culture produced cyanidin 3-monoglucoside, 5, 4′-dihydroxy-7-methoxyisoflavone
4′-glucoside (prunetrin), isoquercitrin, catechin, epicatechin, and procyanidin B-1, B-2, B-3 and B-4, while the pale yellow
cells produced only a small amount of catechin and epicatechin as main flavonoids. These flavonoid compounds found in the
red cell culture were present also in maturePrunus leaves.
Maximum growth and maximum amount of total phenol and proanthocyanidin (procyanidins) were obtained with 0.3 mg/l of both
2,4-D and kinetin. Maximum concentration of anthocyanin was also obtained with 0.3 mg/l 2, 4-D regardless of kinetin concentration.
Accumulation of proanthocyanidin was markedly stimulated by low concentrations of phosphate, which reduced growth by about
half, and also by high concentrations of inorganic nitrogen. Production of both anthocyanin and proanthocyanidin was reduced
by lowered nitrogen levels. Cell growth and production of all phenolics were inhibited when ammonium ion replaced nitrate
in the medium. 相似文献
6.
Summary We have devised a method whereby any mutagenized cloned DNA from Bacillus subtilis can be reinserted at the original site on the B. subtilis chromosome. The procedure depends on the accuracy and high frequency of homologous recombination between the B. subtilis chromosome and the DNA taken up by the cell. The method makes use of two drug resistance selection markers (the chloramphenicol resistance gene and the neomycin resistance gene) and a marker gene which functions as a catalyst. The utility of the method has been demonstrated using leuB and pro of B. subtilis as target gene and catalyst, respectively, and mutations such as leuB: : cat, leuB
–, and pro: : neo constructed in vitro on the cloned DNA fragments. Transformation in sequential steps as (leuB
+ pro+)(leuB: : cat pro
+) (leuB
–
pro: : neo)(leuB
–
pro
+) resulted in a leuB
– single mutant without affecting other regions of the B. subtilis chromosome (gene-directed mutagenesis). We also demonstrate that other single mutations such as metD
– and pro
–, as well as the double mutation leuB
–
pro
– can be introduced by the same procedure. In principle, true isogenies with multiple mutations can be constructed by the method described in this paper. Furthermore, the procedure should be generally applicable to any organisms in which homologous recombination is proficient. 相似文献
7.
8.
Effects of interleukin-12 on in vitro culture with interleukin-2 of regional lymph node lymphocytes from lung cancer patients 总被引:2,自引:0,他引:2
T. Hanagiri Mitsuhiro Takenoyama Takashi Yoshimatsu Chikashi Hirashima Ichiro Yoshino Kozo Nakanishi Akira Nagashima Kikuo Nomoto Kosei Yasumoto 《Cancer immunology, immunotherapy : CII》1996,43(2):87-93
In the present study, we carried out a functional analysis of regional lymph node lymphocytes (RLNL) from patients with lung
cancer after in vitro activation by interleukin-2 (IL-2) and interleukin-12 (IL-12). IL-12 (100 U/ml) enhanced both the proliferation
and cytotoxic activity of RLNL in a culture with low doses of IL-2 (5 – 10 JRU/ml). After comparing an RLNL culture with a
low dose of IL-2 alone, a higher proportion of CD8+ cells and CD56+ cells and a lower proportion of CD4+ cells were found in the culture with both IL-12 and a low dose of IL-2. Such a combination of the cytokines effectively activated
RLNL in terms of the expression of IL-2 receptors. In the culture condition of IL-12 and a low dose of IL-2, a synergistic
effect was observed in the production of such cytokines as interferon γ, tumor necrosis factor α (TNFα), and TNFβ, as well
as in tumor cytotoxicity. However, the addition of IL-12 inhibited the cytotoxicity of RLNL in the culture with a high dose
of IL-2 (100 JRU/ml). This inhibition is considered to be partially due to the endogenous production of TNFα by lymphocytes,
because the neutralization of TNFα bioactivity partially restored the cytotoxic activities of RLNL. Furthermore, in the presence
of hydrocortisone, IL-12 synergistically enhanced the cytotoxic activity of RLNL cultured with a high dose of IL-2. These
results provide useful information about the improvement of adoptive immunotherapy against cancer using RLNL.
Received: 2 February 1996 / Accepted: 30 July 1996 相似文献
9.
Koji Tamada Mamoru Harada Tadao Okamoto Mitsuhiro Takenoyama Osamu Ito Goro Matsuzaki Kikuo Nomoto 《Cancer immunology, immunotherapy : CII》1996,41(6):339-347
In order to expand tumor-infiltrating lymphocytes (TIL) efficiently and in order to use them for immunotherapy, we utilized lipopolysaccharide-activated B cells (LPS blasts) as costimulatory-signal-providing cells in an in vitro culture system. TIL, prepared from subcutaneously inoculated B16 melanoma, failed to expand when cultured with anti-CD3 monoclonal antibody (mAb) alone followed by a low dose of interleukin(IL)-2. In contrast, such TIL did expand efficiently in culture with both anti-CD3 mAb and LPS blasts followed by culture with IL-2. These findings suggest that the presence of LPS blasts in the initial culture was essential for the cell expansion. The expansion of TIL was partially blocked by the addition of CTLA4 Ig, which is an inhibitor of costimulatory molecules such as CD80 and CD86, and was almost blocked by the addition of anti-(Fc receptor II)mAb. These findings thus indicate that such molecules, in conjunction with the receptor on the LPS blasts, participate in the efficient expansion of TIL. The B16-derived TIL, which expanded in our culture system, were predominantly CD8+T cells and showed a higher level of cytolytic activity against B16 melanoma than either lymphokine-activated killer cells or TIL cultured with a high dose of IL-2. In addition, the in vitro expanded B16-derived TIL produced interferon , but not IL-4, in response to B16 melanoma. What is more important, the adoptive transfer of such TIL had a significant antitumor effect against pulmonary metastasis in B16 melanoma, even without the concurrent administration of IL-2. Collectively, our results thus indicate the therapeutic efficacy of the protocol presented here for antitumor immunotherapy with TIL.This work was supported in part by a grant from the Ministry of Education, Science and Culture 相似文献
10.
Kenichiro Nakashima Naotaka Kuroda Shinki Kawaguchi Mitsuhiro Wada Shuzo Akiyama 《Luminescence》1995,10(3):185-191
A sensitive peroxyoxalate chemiluminescent (PO-CL) assay for activities of oxidases (uricase, choline oxidase, cholesterol oxidase and xanthine oxidase) which catalyse a formation of hydrogen peroxide was developed using 4,4′-oxalyl-bis[(trifluoromethylsulphonyl)imino]trimethylene-bis(4-methylmorpholinium)trifluoromethanesulphonate as a chemiluminogenic reagent and 2,4,6,8-tetramorpholinopyrimido[5,4-d]pyrimidine as a fluorophore. The standard curve for hydrogen peroxide was linear over the range 1 × 10?7-1 × 10?4 mol/L. Relative standard deviations for oxidase assays were 5.1–12.7% (n = 10). Detection limits were 1 × 10?3 U/mL for uricase, 5 × 10?4 U/mL for choline oxidase, 5 × 10?3 U/mL for cholesterol oxidase and 5 × 10?4 U/mL xanthine oxidase (sample to blank ratio, 3). 相似文献