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41.
Wistar rats with collagen-induced arthritis were intramuscularly injected with the recombinant plasmid pcDNA/sTNF-BD encoding the sequence of the TNF-binding protein domain of variola virus CrmB protein (VARV sTNF-BD) or the pcDNA3.1 vector. Quantitative analysis showed that the histopathological changes in the hind-limb joints of rats were most severe in the animals injected with pcDNA3.1 and much less severe in the group of rats injected with pcDNA/sTNF-BD, which indicates that gene therapy of rheumatoid arthritis is promising in the case of local administration of plasmids governing the synthesis of VARV immunomodulatory proteins.  相似文献   
42.
Full-length BrCSDP2 and BrCSDP4 cold-shock gene sequences of Brassica rapa have been obtained. The isolated genes were shown to belong to a group AtCSP2/AtCSP4 of Arabidopsis thaliana and TsCSDP2/TsCSDP4 of Thellungiella salsuginea genes that encode proteins with a cold-shock domain and two zinc finger motifs. The structure and the allelic variants of these genes have been described and characterized. The identified allelic polymorphism was shown to result both from point substitutions and small indels. Coefficients of total genetic similarity ranged from 1.0 to 0.53. For BrCSDP2 and AtCSDP2, the genetic similarity coefficient was 0.89 and, for BrCSDP4 and AtCSDP4, it was 0.85. The in silico translation of gene sequences has revealed amino acid substitutions in the protein sequence, but no significant correlation between the detected polymorphism and signs of resistance to cold stress were found.  相似文献   
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44.
1. Specialisation in dispersal by alate aphids often imposes constraints on other functions, particularly a reduction in fecundity due to wing development. Short‐distance flight from patches of high population density to uninfested plants may provide temporary predator‐free space, compensating for low fecundity. However, this theoretical prediction has not been explored experimentally. 2. To test this hypothesis, a field cage experiment was conducted in which Aphis glycines populations initiated with controlled proportions of apterous and alate individuals were exposed to predation, while predator‐free space was accessible only through flight. It was predicted that an investment in alate individuals would benefit a population under predation, regardless of associated costs to fecundity. 3. As expected, a strong trade‐off was observed between fecundity and wing development. However, populations initiated with a fixed proportion of alate and apterous individuals showed no reductions in final population size compared with populations initiated with apterous individuals exclusively. Moreover, the initial presence of alate individuals in the populations increased aphid prevalence (i.e. proportion of plants colonised). Similarly, both increased population size and prevalence were observed when predator‐free space was accessible through flight, as opposed to when it was inaccessible. 4. These results show that despite high costs to fecundity, an investment in alate individuals is neither beneficial nor detrimental to population size when predator‐free space is accessible, but increases aphid prevalence. It is concluded that prevalence might provide an ecological advantage important enough to warrant the production of alate morphs under intense predation.  相似文献   
45.
This study investigates the in vitro modulatory effects of interferon‐γ (IFN‐γ) and interleukin‐4 (IL‐4) on both proliferative bovine T cell responses and IL‐10 production induced by different antigens [crude larval extract and the purified fractions hypodermin A, B and C (HyA, HyB, HyC)] obtained from first instars of Hypoderma lineatum (Diptera: Oestridae), alone or in the presence of the mitogen concanavalin A. Incubation with the different parasitic antigens resulted in significant inhibition of T cell proliferation and IL‐10 production, which, in general, did not revert after the addition of IFN‐γ and IL‐4. In the absence of antigens, IL‐4 induced significant inhibition of mitogen‐induced T cell responses. Exogenous IFN‐γ exhibited an inhibitory effect on cell proliferation in the presence of the purified fractions HyB and HyC. These in vitro data suggest that far from neutralizing the effects of larval antigens, the addition of IFN‐γ potentiates their anti‐proliferative activity; by contrast, IL‐4 had no consistent effects on proliferative responses to Hypoderma. IL‐4 provoked an increment of IL‐10 levels in supernatants of HyB‐stimulated cells. In conclusion, exogenous IFN‐γ and IL‐4 were unable to counteract the suppressor effects of H. lineatum antigens.  相似文献   
46.
The radioimmunological method was applied to determination of changes in the peripheral blood plasma level of 12 steroids in male Papio hamadryas under immobilization and surgical stress. Androgen content decreased, and the concentration of steroid hormone precursors and hydrocortisone blood plasma content rose in response to stress. These changes were in contraphase with the circadian steroid rhythms. The most objective and sensitive criteria of the stress situation evaluation were decrease of testosterone and dihydrotestosterone level, increase of pregnenolone concentration, as well as of 17-alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone in the blood plasma.  相似文献   
47.
Enrichment and pure cultures of hyperthermophilic archaea capable of anaerobic growth on one-carbon compounds (CO and/or formate) were obtained from deep-sea sites of hydrothermal activity at the Mid-Atlantic Ridge, Lau Basin, and Guaymas Basin. All isolates belonged to the T. barophilus?T. paralvinellae group within the genus Thermococcus. In all cases available for analysis, the genomes of Thermococcus strains capable of growth by hydrogenogenic utilization of CO and/or formate contained clusters of genes encoding energy-converting hydrogenase and either CO dehydrogenase or formate dehydrogenase and formate transporter. Apart from the previously known processes of hydrogenogenic oxidation of CO and formate, the oxidation of these substrates coupled to sulfur reduction was observed, processes previously unknown among archaea. The capacities for hydrogenogenic or sulfidogenic oxidation of CO and formate occurred in the studied strains in all possible combinations, which could only in part be explained by peculiarities of organization of genetic determinants revealed in the genomes. Investigation of CO and formate consumption kinetics revealed that T. barophilus strain Ch5 was able to grow at concentrations close to the environmental ones. Thus, it was shown that hyperthermophilic archaea from deep-sea hydrothermal vents are able to utilize one-carbon substrates of abiotic origin both in the presence of an electron acceptor (sulfur) and in its absence. These processes were probably of importance under the conditions of the early Earth biosphere.  相似文献   
48.
Microorganisms in dental plaque live in constant association with saliva. The role of saliva in the adherence of bacteria to the teeth and the antibacterial properties of saliva have been well investigated; less interest has been shown in the possible role of saliva as a substrate for oral microorganisms. In this study it was shown that saliva can serve as a growth medium for oral Streptococcus spp. and Actinomyces viscosus. The cell production of these organisms on saliva was carbohydrate limited. The doubling times for growth on glucose-supplemented saliva (4 to 5 mmol/liter) ranged from 1.6 to 4.0 h. The availability of carbohydrate sources for the oral microflora is discussed in relation to microbial growth in the oral cavity.  相似文献   
49.
Polymorphisms in genes of circadian system family seem to be of most importance for understanding of mechanisms underlying self-assessed individual variation in morning–evening preference. A review of earlier reported positive findings indicated that, at least, four polymorphisms in period circadian clock 3 (PER3) showed significant association with, at least, one of sub-constructs of a morningness–eveningness scale. However, similar to other candidate gene studies, these studies suffer from increased likelihood of false positive findings. We tried to replicate some of the most recently published positive results on associations of sub-traits of morningness–eveningness with two PER3 non-synonymous single nucleotide polymorphisms. DNA from buccal swabs was collected from healthy residents of three Russian cities, Moscow (N = 149) and Novosibirsk and Stavropol (N = 248). The tested hypotheses were formulated in accord with the earlier reported positive findings: the rare alleles might be linked to a higher score on (i) morning earliness–lateness scale (rs2640909, Moscow data-set) and (ii) both morning and evening earliness–lateness scales (rs228729, Novosibirsk and Stavropol datasets). The results provided support for the former hypothesis. These and earlier reported results highlighted several critical issues that remained to be addressed in future independent replications of positive findings on potential genetic markers for morning and evening earliness–lateness.  相似文献   
50.
Abstract:  A revision of thelodont scales from the Lower Devonian of the Iberian Chains enables their grouping into two taxa: Turinia pagei and T. nachoi sp. nov. These taxa are clearly distinguishable by morphological and histological features; they also have a different stratigraphic range ( T. pagei is restricted to Lochkovian strata, whereas T. nachoi sp. nov. occurs within lower–middle Pragian rocks). The new species is represented by head, transitional (cephalopectoral) and trunk scales.  相似文献   
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