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排序方式: 共有253条查询结果,搜索用时 281 毫秒
91.
DiCostanzo CA Moore MC Lautz M Scott M Farmer B Everett CA Still JG Higgins A Cherrington AD 《American journal of physiology. Endocrinology and metabolism》2005,289(1):E46-E52
We examined the extent to which priming the liver with a pulse of Humulin or the insulin analog hexyl-insulin monoconjugate 2 (HIM2) reduces postprandial hyperglycemia. Somatostatin (0.5 microg.kg(-1).min(-1)) was given with basal intraportal insulin and glucagon for 4.5 h into three groups of 42-h-fasted conscious dogs. From 0-5 min, group 1 (BI, n = 6) received saline, group 2 (HI, n = 6) received a Humulin pulse (10 mU.kg(-1).min(-1)), and group 3 (HIM2, n = 6) received a HIM2 pulse (10 mU.kg(-1).min(-1)). Duodenal glucose was infused (5.0 mg.kg(-1).min(-1)) from 15 to 270 min. Arterial insulin in BI remained basal (6 +/- 1 microU/ml) and peaked at 52 +/- 15 (HI) and 164 +/- 44 microU/ml (HIM2) and returned to baseline by 30 and 60 min, respectively. Arterial plasma glucose plateaued at 265 +/- 20, 214 +/- 15, and 193 +/- 14 mg/dl in BI, HI, and HIM2. Glucose absorption was similar in all groups. Significant net hepatic glucose uptake occurred at 85, 55, and 25 min in BI, HI, and HIM2, respectively. Nonhepatic glucose clearance at 270 min differed among groups (BI, HI, HIM2): 0.62 +/- 0.11, 0.76 +/- 0.26, and 1.61 +/- 0.29 ml.kg(-1).min(-1) (P < 0.05). A brief (5-min) insulin pulse improved postprandial glycemia, stimulating hepatic glucose uptake and prolonging enhancement of nonhepatic glucose clearance. HIM2 was more effective than Humulin, perhaps because its lowered clearance caused higher levels at the liver and periphery and its biological activity was not reduced proportionally to its decreased clearance. 相似文献
92.
Using ontologies to describe mouse phenotypes 总被引:1,自引:1,他引:0
The mouse is an important model of human genetic disease. Describing phenotypes of mutant mice in a standard, structured manner that will facilitate data mining is a major challenge for bioinformatics. Here we describe a novel, compositional approach to this problem which combines core ontologies from a variety of sources. This produces a framework with greater flexibility, power and economy than previous approaches. We discuss some of the issues this approach raises. 相似文献
93.
Argyris J Truco MJ Ochoa O Knapp SJ Still DW Lenssen GM Schut JW Michelmore RW Bradford KJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(7):1365-1376
Seed and seedling traits related to germination and stand establishment are important in the production of cultivated lettuce
(Lactuca sativa L.). Six seed and seedling traits segregating in a L. sativa cv. Salinas x L. serriola recombinant inbred line population consisting of 103 F8 families revealed a total of 17 significant quantitative trait loci
(QTL) resulting from three seed production environments. Significant QTL were identified for germination in darkness, germination
at 25 and 35°C, median maximum temperature of germination, hypocotyl length at 72 h post-imbibition, and plant (seedling)
quality. Some QTL for germination and early seedling growth characteristics were co-located, suggestive of pleiotropic loci
regulating these traits. A single QTL (Htg6.1) described 25 and 23% of the total phenotypic variation for high temperature germination in California- and Netherlands-grown
populations, respectively, and was significant between 33 and 37°C. Additionally, Htg6.1 showed significant epistatic interactions with other Htg QTL and a consistent effect across all the three seed production environments. L. serriola alleles increased germination at these QTL. The estimate of narrow-sense heritability (h2) of Htg6.1 was 0.84, indicating potential for L. serriola as a source of germination thermotolerance for lettuce introgression programs. 相似文献
94.
Metabolic fate of 3,4-dichloropropionanilide in plants: the metabolism of the propionic Acid moiety
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Still GG 《Plant physiology》1968,43(4):543-546
3,4-Dichloropropionanilide-14C (propanil) labeled in either the C-1 or C-3 carbon atoms of the propionic acid moiety was applied to the roots of pea (Pisum sativum L.) and rice (Oryza sativa L.) plants in nutrient solution (0.1 mm-0.28 mm). Radioactivity was detected throughout the treated plants, but the greatest labeling was found in the roots. None of the products that contained aniline were radioactive, suggesting that the plants split the propionic acid moiety from propanil. The fate of the propionate moiety of propanil was determined by recovery of 14CO2 from plants exposed to propanil-14C. The time-course of the 14CO2 production demonstrated that the intact propionic acid was cleaved from the propanil and subsequently catabolized by the β-oxidation catabolic sequence. The appearance of radioactivity in the shoots was attributed to the incorporation of products of propionate metabolism. Both the susceptible pea plants and the tolerant rice plants converted a high percentage of the administered propanil-14C to 14CO2. 相似文献
95.
Olfactory sensitivity in tsetse flies: a daily rhythm 总被引:3,自引:0,他引:3
The diurnal tsetse Glossina morsitans morsitans bites especially in early
morning and late afternoon; around midday feeding is at a low. In
laboratory apparatus that measures the amount of locomotion under constant
conditions over the photophase, the flies display a similar patterning of
activity levels. The profile of daily rhythms for G. morsitans reported in
the literature includes a number of motor and sensory motor systems that
fluctuate cophasically. Lacking is a study on the patterning of the senses'
response levels. In this paper we present the first instance of a daily
modulation in the sense of smell. We stimulated the antennae with
concentration series of host-derived odours and measured the spiking rate
of cells at different times during the photophase. The
concentration-response curves suggest that the sensitivity of antennal
olfactory cells flows in parallel with the other daily rhythms. This was
also reflected in electroantennograms (EAGs). The electroantennography was
extended to G. fuscipes fuscipes, whose level of spontaneous locomotor
activity--instead of following a U- shaped pattern--rises gradually over
the photophase. Again, the EAGs appeared to parallel the species' locomotor
activity. What we believe happens is that the organism tones down the
sensitivity of its odour receptors during periods of anticipated inactivity
for reasons of economy.
相似文献
96.
Still P. E. Plata M. I. Campbell R. J. Bueno L. C. Chichester E. A. Niblett C. L. 《Plant Cell, Tissue and Organ Culture》1987,9(1):37-43
Highly morphogenic callus cultures were isolated from stamens of a wild peanut species, Arachis paraguariensis. These cultures were initiated on modified N6 medium containing 0.2 mg1l-1 4amino-3,5,6-trichloro-picolinic acid (picloram) and 0.5 mg l-1 6-benzylaminopurine (BAP) and were maintained on modified N6 medium with 0.008 mg l-1 picloram and 0.25 mg l-1 BAP. Buds formed on the calli growing on the maintenance medium developed into shoots when they were transferred to a MS salts based medium with no hormones. The cultures could also be maintained as a suspension culture in N6 liquid medium. When cell clumps larger tham 840 m were collected from the suspension culture and transferred to MS medium without hormones, they formed shoots in liquid culture. Root formation rarely occurred in agar or liquid cultures. Therefore, grafting to stems of rooted seedlings was used to obtain plants from regenerated shoots. Eight out of 50 field grown plants produced viable seed. 相似文献
97.
A.W. Still 《Animal behaviour》1982,30(3):873-880
Experiments published in Animal Behaviour in 1979 are reviewed, and it is concluded that there are grounds for thinking that the numbers of animals used could sometimes be reduced without loss of scientific rigour. Principles underlying the choice of number of subjects (N) are outlined, and illustrated with examples from the 1979 sample. Several alternatives to increasing N in order to increase power are given, including better design, larger α, and sequential methods. The logic of inference from experiments with small N is discussed. 相似文献
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