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The patterns of disulfide bridges in proteins were considered by using the concept of topological information content. It was proposed that the difference between topological informal ion content in the half-cystine residues of the native state and of the fully reduced form of a protein is related to the problems of the renaturation of the fully reduced and denatured protein. Specifically, when there is no difference between the topological information contents of the two states, the reduced protein is able to recover its native conformation. The concept reported in the present paper is consistent without exception with reported experimental results. 相似文献
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N-hydroxy-2-naphthylamine (NOH-2NA). an active metabolite of human occupational bladder carcinogens, induced, in V79 Chinese hamster cells. chromosomal aberrations which were suppressed in the presence of catalase and/or superoxide dismutase. The induction of the aberrations was more efficient in a more basic pH in parallel with the generation of hydrogen peroxide from NOH-2NA. The possible role of the oxidation product of NOH-2NA in the induction of the aberrations is discussed. 相似文献
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K Ochi 《Journal of general microbiology》1990,136(12):2405-2412
A relaxed (rel) mutant was found among 70 thiopeptin-resistant isolates of Streptomyces coelicolor A3(2) which arose spontaneously. The ability of the rel mutant to accumulate ppGpp during Casamino acid deprivation was reduced 10-fold compared to the wild-type. Analysis of the ribosomal proteins by two-dimensional PAGE revealed that the mutant lacked a ribosomal protein, tentatively designated ST-L11. It was therefore classified as a relC mutant. The mutant was defective in producing A-factor and the pigmented antibiotic prodigiosin, in both liquid and agar cultures, but produced agarase normally. Production of actinorhodin, another pigmented antibiotic, was also abnormal; it appeared suddenly in agar cultures after 10 d incubation. Although aerial mycelium still formed, its appearance was markedly delayed. Whereas liquid cultures of the parent strain accumulated ppGpp, agar cultures accumulated only trace amounts. Instead, a substance characterized only as an unidentified HPLC peak accumulated intracellularly in the late growth phase, just before aerial mycelium formation and antibiotic production. This substance did not accumulate in mutant cells. It was found in S. lividans 66 and S. parvulus, but not in seven other Streptomyces species tested. The significance of these observations, and the relationship of the mutant to earlier rel isolates of Streptomyces is discussed. 相似文献
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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
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N. Ikeda Y. Saito J. Shimizu A. Ochi J. Mizutani J. Watabe 《Journal of applied microbiology》1994,77(2):185-194
Variations between and within individuals, and correlations between concentrations of bacterial metabolites, including putrefactive products, ammonia and short chain fatty acids (SCFAs), enzyme activities, moisture and pH, as well as bacterial composition, were studied in faecal samples from seven healthy adults over a period of 7 months. Large variations, both between and within individuals, were observed in concentrations of putrefactive products. Although values for ammonia, SCFAs, enzyme activities, moisture and pH were generally variable, significant person-to-person differences were observed.
While ranges of log viable counts of the predominant bacteria such as eubacteria, bifidobacteria and bacteroides in each subject remained between 0·2 and 1·3, those of enterobacteria, streptococci (including enterococci) and lecithinase-negative clostridia varied between 0·4 and 3·0. Levels of bifidobacteria, enterobacteria, streptococci and total aerobic bacteria showed inter-individual variations. Correlations were found among certain of the parameters: moisture correlated negatively with p -cresol ( r = -0·707), pH ( r = -0–671) and β-glucosidase activity (GS) ( r = -0·608), and positively with acetic acid ( r = 0·621), while negative correlations were observed in pH with acetic and butyric acids ( r = -0·690 and -0·623, respectively).
No significant correlations were found between bacterial compositions, and other faecal factors such as pH, moisture, metabolic enzyme activities and concentrations of putrefactive products. 相似文献
While ranges of log viable counts of the predominant bacteria such as eubacteria, bifidobacteria and bacteroides in each subject remained between 0·2 and 1·3, those of enterobacteria, streptococci (including enterococci) and lecithinase-negative clostridia varied between 0·4 and 3·0. Levels of bifidobacteria, enterobacteria, streptococci and total aerobic bacteria showed inter-individual variations. Correlations were found among certain of the parameters: moisture correlated negatively with p -cresol ( r = -0·707), pH ( r = -0–671) and β-glucosidase activity (GS) ( r = -0·608), and positively with acetic acid ( r = 0·621), while negative correlations were observed in pH with acetic and butyric acids ( r = -0·690 and -0·623, respectively).
No significant correlations were found between bacterial compositions, and other faecal factors such as pH, moisture, metabolic enzyme activities and concentrations of putrefactive products. 相似文献