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排序方式: 共有442条查询结果,搜索用时 7 毫秒
1.
D Oth M Bégin P Bischoff J Y Leroux G Mercier C Bruneau 《Biochimica et biophysica acta》1987,900(2):198-208
Adriamycin and mitomycin C were previously found to modulate the sensitivity of lymphoma cells to lysis by certain effectors of immunity and this modulation was dependent on drug concentration. In the present studies, RDM4 lymphoma cells were treated with different concentrations of the two drugs for 24 h in culture. These treatments resulted in changes in the lipid composition, membrane fluidity, cell size distribution, and permeability to 51CrO4, Trypan blue, Acridine orange and trimethylaminodiphenylhexatriene (TMA-DPH) of the cells. Changes in some of these parameters, as a function of drug concentration, resulted in dose-response curves which were bell-like shaped, hence paradoxical similarities between non-drug-treated cells and cells treated with higher drug concentrations were observed. 相似文献
2.
Differential effects of glucocorticoids on the proliferation of a murine helper and a cytolytic T cell clone in response to IL-2 and IL-4 总被引:2,自引:0,他引:2
The proliferation of murine T cell clones can be supported by IL-2 or by IL-4. We present here evidence that glucocorticosteroids differentially affect these two pathways of proliferation. Dexamethasone (DEX) and other corticosteroids were observed to induce autocrine proliferation of the D10.G4.1 Th cell clone (D10) in the presence of the anti-clonotypic antibody 3D3. This effect was inhibited by the anti-murine IL-4 antibody 11B11, indicating that it is mediated by IL-4. Furthermore, on this cell line, representative of the Th2 group of helper cells, DEX had little effect on the proliferation induced by exogenous IL-4 but completely inhibited the growth-promoting effects of IL-2. In contrast, the effects of DEX on the proliferation of the cytotoxic IL-2-dependent CTLL-2 cell line are completely opposite. DEX blocked the IL-4-driven proliferation of CTLL-2 cells, while leaving unaffected their response to IL-2. It is also shown in this study that the effects of glucocorticoids in this system are totally antagonized by the high affinity anti-glucocorticosteroid RU 38486, indicating that they are mediated through the described intracellular glucocorticoid receptor. These data suggest that the growth effects of IL-2 and IL-4 may be mediated by distinct pathways that are strikingly different in their sensitivity to glucocorticoids. In addition, the regulation of lymphokine-dependent proliferation and the response to glucocorticoids appeared very different in helper and cytotoxic cells. 相似文献
3.
The continuous infusion of a low dose of glucagon (35 g/kg/d, for 5 d) constitutes, in view of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activities , a reliable experimental model of hyperglucagonemia. By conjunction of monooxygenase assays and immunoquantitation of specific isozymes of cytochrome P-450, the actual inducing ability of glucagon has been shown and it might explain some of the modifications of the drug metabolizing system in diabetic mice. The isozymic pattern of cytochrome P-430 of liver microsomes from diabetic mice appears very different from that produced by classical inducers. 相似文献
4.
Metabolic regulation in enzyme-deficient red cells 总被引:1,自引:0,他引:1
5.
The content of reduced glutathione and of glutathione disulfide as well as the activities of glutathione reductase, glutathione peroxidase, glutathione S-transferases, catalase and superoxide dismutases were determined in human hepatoma Hep 3B cells in relation to free-radical toxicity in order to appreciate the defense capacities of these cells compared to data on normal hepatocytes. When Hep 3B cells were exposed to lindane, a known inducer of free-radical production, superoxide dismutase activity appeared as the best-adapted cellular parameter for early detection of the resulting free-radical toxicity.Abbreviations AAS
atomic absorption spectrometry
- CDNB
1-chloro-2,4-dinitrobenzene
- DMEM
Dulbecco's modified Eagle medium
- GPx
glutathione peroxidase
- G.Red
glutathione reductase
- GSH
reduced glutathione
- GSSG
glutathione disulfide
- GST
glutathione S-transferases
- Prot
proteins
- SOD
superoxide dismutase 相似文献
6.
Iciar Martinez Bent Dreyer Aasta Agersborg Annick Leroux Gilles Boeuf 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》1995,112(4)
Rearing of 1-year-old Arctic charr (Salvelinus alpinus) at 12°C, as well as the administration of 50 or 75 mgT3/kg feed, accelerated the neonatal to adult fast myosin heavy chain transition, but the effect of temperature was more dramatic than the effect of T3 administration. The endogenous plasma levels of T3 in charrs reared at 12°C were higher than those of analogous groups reared at natural temperature, which in the period under study was between 0.5 and 12°C. As in other species, T3 seemed to play a role in the regulation of the neonatal to adult fast myosin isoform transition by down-regulating the levels of the neonatal and increasing the levels of an adult fast myosin heavy chain. Temperature seemed to accelerate this transition at least, but not only, by inducing an increase in the endogenous levels of T3 in the Arctic charr. 相似文献
7.
F. Leboulenger I. Perroteau P. Netchitailo I. Lihrmann P. Leroux C. Delarue D.H. Coy H. Vaudry 《Peptides》1984,5(2):299-303
Vasoactive intestinal peptide (VIP) is located in chromaffin cells of the frog adrenal gland and is able to stimulate corticosteroid secretion in amphibians. In the present study we have investigated the possible involvement of prostaglandins, microfilaments and calcium in the mechanism of action of VIP on frog adrenocortical tissue. Rana ridibunda interrenal dice were perifused with amphibian culture medium for more than 10 hours. Corticosterone and aldosterone concentrations were measured in the effluent perifusate using sensitive and specific radioimmunoassay methods. In the presence of indomethacin (5 μM), a specific blocker of prostaglandin biosynthesis, the spontaneous secretion of corticosteroids was markedly reduced (80%) but the stimulatory effect of VIP was not altered. The administration of the microfilament disrupting agent cytochalasin B (50 μM) inhibited both spontaneous and VIP-induced corticosteroid secretion. In the absence of calcium, the spontaneous level of corticosteroid was reduced to about 60% but VIP was still able to stimulate corticosteroid secretion. From these data we conclude that the integrity of the cytoskeleton is required for the secretory response of adrenocortical cells to VIP, whereas neither prostaglandins nor calcium are involved in VIP-induced adrenocortical stimulation. 相似文献
8.
Comparative trial of treatment with Prioderm lotion and Kwellada shampoo in children with head lice.
The safety and efficacy of treatment with a new pediculicide lotion, Prioderm (0.5% malathion in isopropanol), were compared with those of treatment with Kwellada (1% lindane) shampoo in a randomized trial of children with head lice. The children''s scalps were examined for live lice immediately, 7 days and 4 to 6 weeks following treatment. To determine the in-vitro ovicidal effect of treatment, samples of hair with nits were removed before and immediately following treatment; the subsequent rates of hatching were compared. No live lice were present immediately following either treatment. At 7 days after treatment 2 of the 29 children treated with Prioderm lotion and 4 of the 33 children treated with Kwellada shampoo were infested with live lice, whereas at 4 to 6 weeks after treatment 5 and 3 children respectively were infested. The initial effectiveness of treatment was 93% in the children treated with Prioderm lotion and 88% in those treated with Kwellada shampoo; however, a large difference in efficacy could have been missed owing to the small number of children in the study. Both preparations demonstrated in-vitro ovicidal activity, but neither totally abolished post-treatment hatching. No side effects were reported from either preparation. Because ovicidal activity was incomplete two treatments with the same pediculicides should be given about 7 days apart. 相似文献
9.
10.
P Beaune P Dansette J P Flinois S Columelli D Mansuy J P Leroux 《Biochemical and biophysical research communications》1979,88(3):826-832
Human liver cytochrome P 450 was partially purified by hydrophobic chromatography on Octyl-Sepharose, followed by ion-exchange chromatography on DEAE-cellulose. Two fractions (A and B) were obtained; cytochrome P 450 of fraction A was purified sixfold, with an overall yield of about 6 %. Its spectral properties were similar to those previously described in animal cytochromes P 450. Moreover, p-nitroanisole-O-demethylase activity could be obtained in a reconstituted system involving cytochrome P 450 of fraction A, human NADPH-cytochrome reductase and phospholipids. 相似文献