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81.
Interferon action: binding of viral RNA to the 40-kilodalton 2''-5''-oligoadenylate synthetase in interferon-treated HeLa cells infected with encephalomyocarditis virus. 下载免费PDF全文
The 40-kDa 2'-5'-oligoadenylate [(2'-5') (A)n] synthetase isoenzyme was proven to be a mediator of the inhibition of encephalomyocarditis virus (EMCV) replication by interferon (IFN). When activated by double-stranded RNA, this enzyme converts ATP into 2'-5'-oligoadenylate [(2'-5') (A)n], and (2'-5') (A)n was found to accumulate in IFN-treated, EMCV-infected cells. The only known function of (2'-5') (A)n is the activation of RNase L, a latent RNase, and this was also implicated in the inhibition of EMCV replication. Intermediates or side products in EMCV RNA replication, presumed to be partially double stranded, were shown to activate (2'-5') (A)n synthetase in vitro. These findings served as the basis of the long-standing hypothesis that the activator of (2'-5') (A)n synthetase in IFN-treated, EMCV-infected cells is the viral RNA. To test this hypothesis, we have generated a polyclonal rabbit antiserum to the human 40-kDa (2'-5') (A)n synthetase. The antiserum immunoprecipitated, from IFN-treated HeLa cells that had been infected with EMCV, the 40-kDa (2'-5') (A)n synthetase protein in complex with both strands of EMCV RNA. The immunoprecipitate was active in (2'-5') (A)n synthesis even without addition of double-stranded RNA, whereas the immunoprecipitate from IFN-treated, uninfected cells was not. These and other results demonstrate that in IFN-treated, EMCV-infected cells, viral RNA is bound to the (2'-5') (A)n synthetase and suggest that the agent activating the (2'-5') (A)n synthetase is the bound viral RNA. 相似文献
82.
Interferons as gene activators. Characteristics of an interferon-activatable enhancer 总被引:4,自引:0,他引:4
G Gribaudo E Toniato D A Engel P Lengyel 《The Journal of biological chemistry》1987,262(24):11878-11883
Previously we linked a 0.8-kilobase segment (including the 5'-flanking region and the 5'-terminal exon) of an interferon-activatable mouse gene (202 gene) to the chloramphenicol acetyltransferase gene and transfected the construct into mouse Ltk- cells (Samanta, H., Engel, D. A., Chao, H. M., Thakur, A., Garcia-Blanco, M. A., and Lengyel, P. (1986) J. Biol. Chem. 261, 11849-11858). Treatment of these cells with mouse beta-interferon increased the expression of the chloramphenicol acetyltransferase gene 5-10-fold. Here we demonstrate that this segment from the 202 gene has characteristics of an interferon-activatable enhancer: (a) it can activate a heterologous promoter (SV40 early promoter), (b) it is active in both the appropriate and the inverted orientation and in either upstream or downstream locations from the promoter activated, and (c) treatment of cells with interferon increases its activity severalfold. 相似文献
83.
I Lengyel 《American journal of physical anthropology》1984,63(3):283-290
The author reports about the theoretical effects of his paleoserologic investigations on some historical population genetics problems. First he refers to the essence of the two modifications by the help of which the fluorescent antibody method can be made suitable for blood typing or archeological skeletal remains and determines his working units (sample, series, "population") used in the paleoserologic researches. The benefits of the projection of the ABO blood typing results on the map of the cemetaries are demonstrated. The distribution of the several phenotypes are collated to the character or richness of the grave goods and to the taxonomic features of the late individuals. The thorough examination of the serogenetic distances among the several samples of a given historical period may cast more light on the ethnic interrelations of the earlier populations living in the same geographic area. Following up the serogenetic changes of a population during subsequent historical periods, new ideas can be gained about the importance of the environmental, economic, and demographic factors shaping the serogenetic profile of the population. 相似文献
84.
The role of second messengers in the regulation of protein phosphorylation was studied in microvessels isolated from rat cerebral cortex. The phosphoproteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the kinetics of 32P incorporation into specific protein substrates were evaluated by computer-aided x-ray film densitometry. With the use of this method, Ca2+-calmodulin (CAM)-, Ca2+/phospholipid (PK C)-, cyclic GMP (cGMP)-, and cyclic AMP (cAMP)-dependent protein kinases were detected. CAM-dependent protein kinase proved to be the major phosphorylating enzyme in the microvascular fraction of the rat cerebral cortex; the activity of cGMP-dependent protein kinase was much higher than that of the cAMP-dependent one. Autophosphorylation of both the alpha- and beta-subunits of CAM-dependent protein kinase and the proteolytic fragment of the PK C enzyme was also detected. The kinetics of phosphorylation of the individual polypeptides indicate the presence in the cerebral endothelium of phosphoprotein phosphatases. The phosphorylation of proteins in the cerebral capillaries was more or less reversible; the addition of second messengers initiated a very rapid increase in 32P incorporation, followed by a slow decrease. Because the intracellular signal transducers like Ca2+ and cyclic nucleotides are frequently regulated by different vasoactive substances in the endothelial cells, the modified phosphorylation evoked by these second messengers may be related in vivo to certain changes in the transport processes of the blood-brain barrier. 相似文献
85.
Ruis MA de Groot J te Brake JH Dinand Ekkel E van de Burgwal JA Erkens JH Engel B Buist WG Blokhuis HJ Koolhaas JM 《Applied animal behaviour science》2001,70(3):201-225
Endocrine, behavioural and immunologic processes, together with body growth, were evaluated in gilts that were defeated at 10 weeks of age in resident-intruder tests. Immediately after defeat, gilts were either separated from or reunited with a familiar conspecific (litter-mate; always a barrow). Gilts were assigned to one of four treatments: (a) DI: defeat, followed by isolation (separation from original litter-mate; n=8); (b) I: no defeat, isolation (control group; n=9); (c) DP; defeat, followed by pair-housing (reunion with original litter-mate; n=8); and (d) P: no defeat, pair-housing (control group; n=8). The following general conclusions were derived: (1) social defeat caused pronounced short-term elevations in hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal medullary activities, and of prolactin levels. Moreover, as soon as 1h after defeat, percentages of blood lymphocytes and neutrophilic granulocytes were, respectively, decreased and increased; (2) social defeat had some long-lasting influence on behaviour and physiology, but isolation predominantly determined responses in the longer term. Defeat, as well as isolation, resulted in increased cardiovascular activities compared to P controls, as observed in a novel object test (NOT: +7 days) and an aversion test (AVT: +14 days). Moreover, defeated as well as isolated gilts did not habituate to a repeated novel environment test (NET: -7, +2 and +7 days) in terms of frequencies of vocalising, whereas P controls did. Isolation, through the separation from any other pig, was responsible for the other observed long-term characteristics, which developed progressively. Isolated gilts showed high mobilities and high cortisol responses in the repeated NET (+7 days), not being habituated. This contrasted the reactions of pair-housed gilts, which were much reduced. In addition to their high cardiovascular activities in the NOT and the AVT, isolated gilts also displayed higher heart rates in the repeated NET and during human presence following the NOT, compared to pair-housed gilts. Finally, isolated gilts were more inhibited to approach a novel object (in the NOT) than pair-housed pigs; and (3) stress responses of defeated gilts were modulated by the subsequent social environment. Stimulation of the HPA-axis (plasma- and salivary cortisol) was prolonged in those defeated gilts which were isolated (observed in the first hour). Changes in leucocyte subsets were still observed after 3 days in DI, but were 'normalised' within 1 day in DP gilts. Two days after defeat, habituation to the repeated NET in terms of mobility and salivary cortisol responses occurred in control and DP gilts, but not in DI gilts. We argue that these effects of the social environment shortly after defeat were related to a stress-reducing effect of a stable social relationship, i.e. social support. 相似文献
86.
Zusammenfassung Autoren berichten über einen Fall von zweifacher tiefmykotischer Infektion, der ihres Wissens im Schrifttum noch nicht veröffentlicht wurde. Die Diagnose von Darm-Aktinomykose klärte sich erst, als Hauterscheinungen auftraten. Der ungemein hartnäckige Verlauf der Aktinomykose findet wahrscheinlich seine Erklärung in der Blastomykose, die erst durch eine histologische Untersuchung verifiziert wurde.
Summary The authors report a case of a double mycotic inner-infection, such as was never published before that they knew of. The diagnosis of intestine actinomycosis became not clear till appearances on the skin became visible. The uncommonly pertinaceous course of the actinomycosis can probably be explained by the blastomycosis, which was only verified after histological examination.相似文献
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