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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
134.
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
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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
138.
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
139.
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
140.
The study was conducted to identify the mechanisms of endotoxin/cortisol action in the suppression of preovulatory LH surges in heifers infused with Escherichia coli (E. coli ) endotoxin. The hypotheses tested were that 1) endotoxin stimulates the release of progesterone, possibly from the adrenal leading to the LH blockade; 2) cortisol released in response to endotoxin infusion blocks the synthesis of estradiol at the ovarian level, culminating in a failure of the LH surge. Eight Holstein heifers were given two injections of prostaglandin F(2alpha) (PG), 11 d apart, to synchronize estrus. Starting from 25 h after the second injection of PG (PG-2), the uterus of each heifer was infused either with 5 ml of pyrogen-free water (control, n = 3) or with E. coli endotoxin (5 mug/kg of body weight) in 5 ml of pyrogen-free water (treated, n = 5), once every 6 h for 10 treatments. Blood samples were obtained every 15 min for 1 h before infusion and again 2 h after each infusion, then hourly until 1 h before the next infusion. After the tenth infusion, blood was collected daily until estrus. Serum progesterone concentrations remained at baseline values (< 1 ng/ml) in control and treated heifers. The total amount of progesterone measured starting 24 to 84 h after PG-2 injection was not different between control and treated heifers (P 0.05). In the control heifers, serum estradiol concentrations remained basal (< 10 pg/ml) until 4 h before the LH surge. Serum estradiol concentrations increased to 20 +/- 5.6 pg/ml, 4 h before the LH surge in control heifers (LH surge occurred 60 to 66 h after the PG-2 injection). There were no changes in serum estradiol concentrations in treated heifers during the sampling period, and the concentrations remained < 10 pg/ml. The total amount of estradiol measured in control heifers was higher (P < 0.05) than in treated heifers. The results if this study suggest that increases in cortisol concentrations after the infusion of endotoxin might block the synthesis of estradiol at the ovarian level, resulting in the failure of a preovulatory LH surge to occur. 相似文献