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171.
172.
Peter J. Somers Richard N. Gevirtz Susan E. Jasin Homer G. Chin 《Applied psychophysiology and biofeedback》1989,14(4):309-318
This investigation assessed the efficacy of a biobehavioral intervention in the adjunctive treatment of mild pregnancy-induced hypertension (PIH), a potentially serious complication of pregnancy in which normotensive women develop hypertension, proteinuria, and edema of unknown etiology late in gestation. Forty-five women with symptoms of PIH were randomly assigned to one of three treatment conditions: bed rest alone (the most common obstetrical treatment), bed rest with individualized compliance enhancement training, or a four-session biobehavioral treatment consisting of bed rest, compliance enhancement training, and individualized thermal biofeedback-assisted relaxation training. Results indicated that while blood pressure for the bed rest and compliance enhancement groups continued to rise and pose an increasing health risk to maternal and fetal well-being, subjects in the biobehavioral group maintained their blood pressure at a significantly lower, and presumably safer, level. The biobehavioral treatment is hypothesized to affect blood pressure levels in subjects with mild PIH through the mediation of the sympathetic nervous system, decreasing peripheral vascular resistance and cardiac output. The results of this investigation suggest that the biobehavioral intervention may be an effective adjunct to bed rest in the treatment of mild PIH remote from term. 相似文献
173.
Smeekens Sjef Geerts Dirk Bauerle Cynthia Weisbeek Peter 《Molecular genetics and genomics : MGG》1989,217(1):178-181
Molecular Genetics and Genomics - Plant ferredoxin is a nuclear-encoded chloroplast protein that is synthesized in the cytoplasm as a transit peptide-containing precursor molecule. To identify... 相似文献
174.
Gabriele Schulz Klaus Peter Ulbrich Carl Hauenschild Hans-Dieter Pfannenstiel 《Development genes and evolution》1989,198(1):29-33
Summary In most nereids sexual maturation is accompanied by a dramatic reorganization of the body that enables swarming of the formerly benthic worms. However, a border exists between unchanged anterior (atokous) and metamorphosed posterior (epitokous) segments. The site of this atokous-epitokous border (a/e border) is different in sexually mature males and females of Platynereis dumerilii. There is no correlation between the total number of setigerous segments of a specimen and the location of the a/e border. The location of the a/e border and sexual development are affected neither by cutting off caudal segments of juveniles (including the prospective a/e border) nor by transecting the ventral nerve cord. When parapodia are transplanted from prospective epitokous regions to prospective atokous regions and vice versa, they maintain their original character during metamorphosis. The results presented here suggest that prospective atokous as well as epitokous characters are determined at or only very shortly after formation of the respective segments. Thus the a/e border is established well in advance of the onset of epitokous metamorphosis. 相似文献
175.
176.
177.
Summary The molecular evolution of cytochrome c from angiosperms is compared to that from vertebrates. On the basis of a cladistic
analysis from 26 plant species, compared to that from 27 vertebrate species, we find that although the vertebrate sequences
yield reasonably well-defined minimal trees that are congruent with the biological tree, the plant sequences yield multiple
minimal trees that are not only highly incongruent with each other, but none of which is congruent with any reasonably biological
tree. That is, the plant sequence set is much more homoplastic than that of the animal. However, as judged by the relative
rate test, the extent of divergence, and degree of functional constraint, cytochrome c evolution in plants does not appear
to differ from that of vertebrates. 相似文献
178.
Stephen Schibeci Peter Hersey David Cheresh 《Cancer immunology, immunotherapy : CII》1989,29(2):109-117
Summary Previous studies have shown that monoclonal antibodies (mAbs) against certain gangliosides, which induced remissions in patients with melanoma, also potentiated the response of lymphocytes to a variety of stimuli, including lectins, interleukin-2 (IL-2) and antigens. The present studies have investigated the mechanism of these effects on lymphocytes. Although the mAbs potentiated phytohemagglutinin (PHA)-induced IL-2 production at high concentrations of mAbs and of PHA, this did not appear to explain their potentiation of the proliferative responses of lymphocytes. Hence, although IL-2 production was minimal or absent from the CD8+ subset the latter showed the highest degree of augmentation. Furthermore, addition of IL-2 to PHA-stimulated cultures did not produce similar augmentation of mitogenic responses to that produced by the mAb to GD3 or GD2. The augmented and normal mitogenic responses were, however, dependent on IL-2, as shown by their inhibition with mAbs against IL-2. The antiganglioside mAbs did not have significant effects on IL-2 receptor expression measured by mAbs to Tac. However, the mAbs appeared to increase the affinity of binding of radiolabelled IL-2 to IL-2 receptor and increased internalization of the latter. These results suggest that the effects of the mAbs on IL-2 production may be distinguished from their effects on the proliferative responses of T cells and that the latter were associated with changes in affinity and internalization of 125I-IL-2. Whether the latter is a direct cause of the increased proliferative response remains unknown. The ability of mAbs to GD2 and GD3 to increase IL-2 production and to enhance IL-2-dependent proliferative responses suggests the may have valuable clinical roles as immunopotentiating agents. 相似文献
179.
Carbon metabolism in Bradyrhizobium japonicum bacteroids 总被引:2,自引:0,他引:2
Timothy R. McDermott Stephen M. Griffith Carroll P. Vance Peter H. Graham 《FEMS microbiology letters》1989,63(4):327-340
Abstract Carbon metabolism in Bradyrhizobium japonicum bacteroids is reviewed. Additionally, the bacteroid tricarboxylic acid (TCA) cycle and its regulation under oxygen-limited conditions is considered, with emphasis on possible sites of TCA cycle rate-limiting reactions. Furthermore, we consider other adaptive pathways that may be employed by these organisms while in symbiosis. These pathways include: (1) a poly-β-hydroxy-butyrate shunt, (2) a malate-aspartate shuttle, (3) an α-ketoglutarate-glutamate shunt, (4) a modified dicarboxylic acid cycle, and (5) fermentation pathways leading to lactate, acetaldehyde and ethanol. The effects of oxygen limitation on host carbon metabolism are also considered briefly. 相似文献
180.
Dynamics of small autocatalytic reaction networks—I. bifurcations,permanence and exclusion 总被引:1,自引:0,他引:1
Catalysis in replication networks has become an important issue in biophysics and other areas of biology. Examples are RNA
catalysis, idiotype recognition in the immune response and dynamical models of Maynard-Smith games in sociobiology.
Chemical reaction networks describing catalysed, template-induced reproduction of three species are analysed in full generality.
The nine-dimensional parameter space is reduced to three relevant angular coordinates which determine completely the phase
portraits (PPs) and the bifurcation patterns. All cases are classified and all generic as well as most of the nongeneric transitions
are listed and described.
This paper has been reproduced directly from disc using a LA-TEX system. 相似文献