共查询到20条相似文献,搜索用时 15 毫秒
1.
Y. Fujimoto N. Ikekawa M. Ogiso E. Ohnishi 《Cellular and molecular life sciences : CMLS》1986,42(5):567-568
Summary The structures of the metabolites formed upon incubation of 17-estradiol with the ovaries of silkworm,Bombyx mori, have been determined as 17-estradiol 3-(-D-glucopyranoside) (1) and 17-(-D-glucopyranoside) (2) by spectroscopic means. 相似文献
2.
Active oxygen, produced by cultured cells following stimulation with various growth factors, seems to be involved in signal transduction leading to cellular responses such as gene expression and growth modulation. In the present study, the intracellular oxidation state was measured in immortalized human endothelial cells (ECV304) after treatment with tumor necrosis factor (TNF), using a fluorescent dye and a laser-scanning confocal microscope. The intracellular oxidation state was increased 60 min after the addition of TNF, and this increase was abolished by a radical scavenger, N-acetylcysteine (NAC), which is also a precursor of glutathione, and by pyrrolidine dithiocarbamate (PDTC). TNF increased the steady state level of urokinase-type plasminogen activator (uPA), and NAC inhibited this increase at a dose that also inhibited the increase in the intracellular oxidation state. PDTC, on the other hand, did not affect the induction of the uPA gene by TNF. These results suggest that intracellular glutathione level rather than the oxidation state is necessary for the induction of the uPA gene by TNF. 相似文献
3.
Summary Three cultured human cell lines, renal cancer cells (ACHN), bladder cancer cells (EJ), and fibroblasts transformed in culture by Co-60 gamma rays (KMST-6), when treated with interferon-, produced 1.5 to 4 times as much plasminogen activator as the untreated control cultures. This enhanced production of PA was inhibited by cycloheximide or actinomycin D. 相似文献
4.
M. L. Marcante A. Floridi P. G. Natali G. Citro V. Cioli C. De Martino 《Cellular and molecular life sciences : CMLS》1979,35(4):563-565
Summary The estradiol 17-synthesis by 4 pathway has been studied in homogenous cultures of Sertoli cells isolated from adult rat testes. The data reported clearly demonstrate that progesterone, androstenedione, testosterone and estrone induce an increase of the estradiol 17-production.This work was partially supported by grants No. 77.01322.04 and No. 77.01958.04 from the Consiglio Nazionale delle Ricerche.The excellent technical assistance of Antonio Muller and Massimo Rosati is deeply appreciated. 相似文献
5.
Zusammenfassung Quantitative Analysen des-mercaptobrenztraubensäure-spaltenden Enzyms zeigen, dass Zellen, die sich in aktivem mitotischem Prozess befinden (bzw. Krebszellen und Gewebekulturen), dieses Enzym in viel geringerem Masse enthalten als « normale » Zellen. Da dieses Enzym in dem anaeroben Stoffwechsel von Zystein eine wichtige Rolle spielt, lässt sich vermuten, dass sich der Zysteinstoffwechsel der Tumorzelle quantitativ von dem der Normalzelle unterscheidet.
Supported by U.S. Public Health Grants H-2897, C-3211 and by a grant of the American Cancer Society (70-4612-24). 相似文献
Supported by U.S. Public Health Grants H-2897, C-3211 and by a grant of the American Cancer Society (70-4612-24). 相似文献
6.
Yu. Yu. Chirkov A. R. Kazarov M. A. Malatsidze A. S. Sobolev 《Cellular and molecular life sciences : CMLS》1985,41(11):1430-1432
Summary In mixed culture of Chinese hamster fibroblatst, clone 431, and transformed murine L fibroblasts, clone B-82, isoproterenol was found to protect only 431 cells against ionizing radiation. It was shown that 431 cells, in contrast to B-82 cells, possess-adrenoreceptors, and the radioprotective effect of isoproterenol can be realized only if this agent interacts with-adrenoreceptors coupled with the cAMP system. Since malignization often causes the disappearance of-adrenergic and other hormone receptors, the combined culturing and irradiation of the cells studied can be regarded as a model of the growth of malignant cells (B-82) among normal tissue cells (431 cells) under conditions of radiation therapy. A possibility of selective protection against radiation damage of normal tissue cells, with retention of the former radiosensitivity of tumor cells, is discussed. 相似文献
7.
The regulation of IL-17A and IL-22 production differs between human and murine γδ T cells. We find that human γδ T cells expressing
Vγ2Vδ2 T cell receptors are peripherally polarized to produce IL-17A or IL-22, much like CD4 αβ Th17 T cells. This requires
IL-6, IL-1β, and TGF-β, whereas expansion and maintenance requires IL-23, IL-1β, and TGF-β. In contrast, IL-17A and IL-22
production by murine γδ T cells is innately programmed during thymic ontogeny but requires IL-23 and IL-1β for maintenance.
Murine γδ cells producing IL-17A and IL-22 play important roles in microbial, autoimmune, and inflammatory responses. However,
the roles played by human IL-17A- and IL-22-producing γδ T cells are less clear but are also likely to be important. These
observations highlight differences between humans and murine γδ T cells and underscore the importance of IL-17A- and IL-22-producing
γδ T cells. 相似文献
8.
Summary The responsiveness of fetal mouse Leydig cells to catecholamines (epinephrine, norepinephrine), a-agonist agent (L-isoproterenol) and hCG was investigated in vitro. Fetal Leydig cells when freshly isolated were unable to respond to L-isoproterenol (10–5M). However, L-isoproterenol, epinephrine and norepinephrine significantly stimulated androgen production by fetal Leydig cells after 24 h of primary culture. Androgen production was increased in both conditions and to a greater extent by hCG. Propranolol blocked the stimulatory effect of L-isoproterenol and epinephrine. It is concluded that catecholamines can regulate fetal testosterone biosynthesis. 相似文献
9.
The murine epidermis contains resident T cells that express a canonical γδ TCR and arise from fetal thymic precursors. These
cells are termed dendritic epidermal T cells (DETC) and use a TCR that is restricted to the skin in adult animals. DETC produce
low levels of cytokines and growth factors that contribute to epidermal homeostasis. Upon activation, DETC can secrete large
amounts of inflammatory molecules which participate in the communication between DETC, neighboring keratinocytes and langerhans
cells. Chemokines produced by DETC may recruit inflammatory cells to the epidermis. In addition, cell–cell mediated immune
responses also appear important for epidermal–T cell communication. Information is provided which supports a crucial role
for DETC in inflammation, wound healing, and tumor surveillance. 相似文献
10.
Christian Peters Dieter Kabelitz Daniela Wesch 《Cellular and molecular life sciences : CMLS》2018,75(12):2125-2135
γδ T cells share characteristics of innate and adaptive immune cells and are involved in a broad spectrum of pro-inflammatory functions. Nonetheless, there is accumulating evidence that γδ T cells also exhibit regulatory functions. In this review, we describe the different phenotypes of regulatory γδ T cells in correlation with the identified mechanisms of suppression. 相似文献
11.
Summary The cytostatic activity of N-methyl-N--chloroethylbenzaldehyd hydrazone, (B1) is at least equal to that of procarbazine when its effect is tested with the Ehrlich ascites tumor cells of the mouse and the Yoshida sarcoma of the rat. B1 causes a slighter decrease of mitotic cells and no shift from prophase to metaphase. These results suggest that the cytostatic effect of B1 is due to interference with cell metabolism or an effect at the cell membrane and not to an effect on cell proliferation. This assumption is supported by a considerable depression, of lymphocytes and a minor effect on granulopoiesis, which is especially sensitive towards proliferation toxins. All these findings suggest a different mechanism of action of B1 and procarbazine. 相似文献
12.
Rose P Whiteman M Huang SH Halliwell B Ong CN 《Cellular and molecular life sciences : CMLS》2003,60(7):1489-1503
-Phenylethyl isothiocyanate (PEITC) is a promising chemoprotective compound that is
routinely consumed in the diet as its glucosinolate precursor. Previous studies have shown that PEITC
can inhibit phase I enzymes and induce phase II detoxification enzymes along with apoptosis in vitro.
The detailed mechanisms involved in the apoptotic cascade, however, have not been elucidated. In the
present study, we demonstrate that PEITC can induce apoptosis in hepatoma HepG2 cells in a
concentration- and time-dependant manner as determined by TUNEL positive and SubG1 population
analysis. Caspase-3-like activity and poly(ADP-ribosyl)polymerase cleavage increased during
treatment with 20 µM PEITC; high concentrations, however, induced necrosis. Pre-treatment with
Z-VAD-FMK and the caspase-3-specific inhibitor Ac-DEVD-CHO prevented PEITC-induced apoptosis, as
determined by caspase-3-like activity and DNA fragmentation. Additional investigations also showed
that at concentrations of 5-C10 µM PEITC, DNA synthesis was inhibited and G2/M phase cell cycle
arrest occurred, correlating with an alteration in cyclin B1 and p34cdc2 protein levels. Furthermore, we also demonstrate
a concentration- and time-dependant burst of superoxide (O2-)
in PEITC-treated cells. However, pre- and co-treatment with the free radical scavengers Trolox,
ascorbate, mannitol, uric acid and the superoxide mimetic manganese (III) tetrakis (N-methyl-2-pyridyl)
porphyrin failed to prevent PEITC-mediated apoptosis. Taken together, these results suggest that
PEITC potently induces apoptosis and cell cycle arrest in HepG2 cells and that the
generation of reactive oxygen species appears to be a secondary effect.Received 23 December 2002; accepted 22 April 2003 相似文献
13.
H. J. Kim M. Y. Kim J. S. Hwang H. J. Kim J. H. Lee K. C. Chang J. -H. Kim C. W. Han J.-H. Kim H. G. Seo 《Cellular and molecular life sciences : CMLS》2010,67(12):2119-2130
Activation of peroxisome proliferator-activated receptor (PPAR) δ by GW501516, a specific PPARδ ligand, significantly inhibited interleukin (IL)-1β-induced proliferation and migration of vascular smooth muscle cells (VSMCs). This effect of GW501516 was dependent on transforming growth factor-β, and was mediated through the up-regulation of IL-1 receptor antagonist. The inhibitory effect of GW501516 on VSMC proliferation was associated with cell cycle arrest at the G1 to S phase transition, which was accompanied by the induction of p21 and p53 along with decreased cyclin-dependent kinase 4 expression. Inhibition of cell migration by GW501516 was associated with the down-regulation of matrix metalloproteinase (MMP)-2 and MMP-9 in IL-1β-treated VSMCs. Inhibition of extracellular signal-regulated kinase significantly reduced the GW501516-mediated inhibition of IL-1β-stimulated VSMC proliferation. These results suggest that PPARδ plays an important role in the pathophysiology of diseases associated with the proliferation and migration of VSMCs. 相似文献
14.
K. Tohya R. Sugata S. Toda M. Kimura 《Cellular and molecular life sciences : CMLS》1989,45(8):750-753
Summary The in situ activity of 3-hydroxysteroid dehydrogenase was detected in clustered cells which showed steroid-producing morphology, within the capsule of the paraaortic lymph node. In light and electron microscopic studies, the positive reaction products were detected on intracapsular cell clusters. This result indicates that these unique cells may have a steroid secreting function within the lymph nodes. 相似文献
15.
S. Schwarz W. Pohnert A. Stachowiak D. Onken 《Cellular and molecular life sciences : CMLS》1963,19(3):128-129
Summary 5- and 5-androstane-17-ol-3-one-17-acetate have been prepared from 5-androstane-6, 17-diol-3-one-17-acetate by a synthesis involving directedHuang-Minlon-reduction.Separation of 5-androstane-17-ol-3-one from its 5-isomer could readily be achieved by crystallisation of their 3-ethylenketals from acetone. 相似文献
16.
Summary 1--D-Arabinofuranosyl cytosine-5-triphosphate (araCTP), an inhibitor of DNA synthesis, paradoxically enhanced unscheduled DNA synthesis (USD) induced by bleomycin in permeable mouse sarcoma cells. A greater enhancing effect of araCTP on bleomycin-induced USD was observed with lower concentrations of dCTP in the assay mixture. USD measured without bleomycin in nuclei isolated from mouse sarcoma cells was not enhanced, but inhibited by araCTP.Acknowledgments. The authors wish to thank Nippon Kayaku Co. (Tokyo, Japan) for providing copper-free bleomycin A2. This research was supported in part by a grant from the Japan Ministry of Education, Science and Culture. 相似文献
17.
R. Dalwadi-Bhattacharya 《Cellular and molecular life sciences : CMLS》1980,36(1):74-75
Summary The circadian rhythm of rat liver-glucuronidase has been studied in animals kept under highly standardized laboratory condition. A clear 24 h rhythm has been observed for this enzyme with a peak activity at 01.00 h and a trough at 13.00 h.The work was carried out in Institut für Anatomie I, Medical School, Hannover (Federal Republic of Germany). Supported by grants from Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 146 and VW Stiftung, Hannover A2 11.2000. 相似文献
18.
Zusammenfassung Nebennierenschnitte von Ratten, Meerschweinchen und Menschen synthetisierten 17-Hydroxyprogesteron, 11-Deoxycortisol und Cortisol aus 17-Hydroxypregnenolon. Diese Verbindung, als Ausgangsprodukt für die Cortisolsynthese, ist ebenso wirksam wie pregnenolon. Die Umwandlung von 17-Hydroxypregnenolon in Dehydroepiandrosteron verläuft weniger vollkommen als zu 17-Hydroxycorticoiden. 相似文献
19.
Activation of cytotoxic T cells by solid tumours? 总被引:2,自引:0,他引:2
Tumour-specific cytotoxic T cells (CTLs) are among the best-defined biological anticancer weapons. Nevertheless, they often fail to control tumour growth in vivo. Many reasons for this have been evoked tumours may actively inhibit CTLs, or may protect them selves from CTL recognition by various means. However, one does not necessarily need to postulate such active immune evasion mechanisms specifically acquired by tumour cells. In this review we argue that the failure of immune protection is due to the intrinsic inability of tumours to activate an effective immune response, and that many tumours are similar to normal issues in this respect. It is striking to see that the majority of the so-called immune escape mechanisms are not specifically acquired by selected tumour cells, but are common mechanisms shared between solid tumours and normal, healthy tissues. Immune responses are poor because tumour antigens do not efficiently localize to lymph follicles in lymphoid tissues, and are not efficiently presented to CTLs in an immunogenic context. The fact that tumours do not induce CTLs but are often susceptible to lymphocyte-mediated cytotoxicity indicates that more intensified immunization protocols should result in improved clinical outcome. 相似文献
20.
Chen ZW 《Cellular and molecular life sciences : CMLS》2011,68(14):2409-2417
Accumulating evidence suggests that human γδ T cells act as non-classical T cells and contribute to both innate and adaptive
immune responses in infections. Vγ2 Vδ2 T (also termed Vγ9 Vδ2 T) cells exist only in primates, and in humans represent a
dominant circulating γδ T-cell subset. Primate Vγ2 Vδ2 T cells are the only γδ T cell subset capable of recognizing microbial
phosphoantigen. Since nonhuman primate Vγ2 Vδ2 T cells resemble their human counterparts, in-depth studies have been undertaken
in macaques to understand the biology and function of human Vγ2 Vδ2 T cells. This article reviews the recent progress for
immune biology of Vγ2 Vδ2 T cells in infections. 相似文献