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Viprostol, a novel prostaglandin E2 congener, was assessed for in vitro antilipolytic activity in the spontaneously obese rat. In isolated epididymal adipocytes, viprostol exhibited a dose-dependent inhibition of catecholamine-stimulated lipolysis at concentrations ranging from 10 microM to 1 mM, but was ineffective at lower concentrations. Additionally, viprostol exhibited approximately 50% of the antilipolytic activity of naturally-occurring PGE1 and PGE2 at similar concentrations, but was as potent as PGF2 alpha. At 10 microM, viprostol inhibited maximum catecholamine-stimulated lipolysis by approximately 35% of the total, hormone-stimulated glycerol release. The results of these experiments indicate that viprostol exhibits antilipolytic activity in vitro, but is less potent than the naturally-occurring PGE's to which it is most closely related structurally.  相似文献   
54.
Summary A basic procedure was developed to produce a tempe-like product using the mouldRhizopus oligosporus and black common beans (Phaseolus vulgaris) as substrate. The initial pH of the substrate was 5.8, and fermentation was conducted at 37°C with a relative humidity of 70% for 72 hrs. Levels of soluble solids and soluble protein increased dramatically as a result of fermentation. Some changes were as well observed in fatty acid contents of fermented samples. It was concluded that the common bean used was an acceptable substrate for preparing this product.  相似文献   
55.
Various chemicals commonly found in food (twelve monosaccharides, nine sugar alcohols, twenty triglycerides, eleven unsaturated fatty acids and nine saturated fatty acids) were tested in different concentrations for their ability to attract and sustain feeding by the dried-fruit mite,Carpoglyphus lactis (L.). Oleic acid, -d-glucose and some triglycerides act as phagoincitants and phagostimulants, whiled-fucose and trilaurin are phagodeterrents.  相似文献   
56.
Big Moose Basin: simulation of response to acidic deposition   总被引:2,自引:1,他引:1  
The ILWAS model has been enhanced for application to multiple-lake hydrologic basins. This version of the model has been applied to the Big Moose basin, which includes Big Moose Lake and its tributary streams, lakes, and watersheds. The basin, as defined, includes an area of 96 km2, with over 20 lakes and ponds, and 70 km of streams. Hydrologic and chemical calibrations have been made using data from seven sampling stations. When total atmospheric sulfur loading to the basin is halved, the model predicts, after four years of simulation, a decreasing sulfate concentration and to a lesser extent a rising alkalinity at Big Moose Lake outlet. At the end of four years, the results show an increase in pH of 0.1 to 0.5 pH units depending upon season.  相似文献   
57.
Eighteen sows (6 primiparous and 12 multiparous) were allotted randomly within parity to two lactational treatments: litter separation (LS; 6 h/day) plus boar exposure (BE; 1 h/day; N = 14) beginning 8 days before weaning (4 weeks) and no LS + no BE (controls; N = 4). Blood was collected from all sows via indwelling venous catheters at 20-min intervals for 5 h on Days -1, 0, 1, 2 and 3 from start of treatment. Control sows and those exposed to LS + BE not exhibiting oestrus during lactation were resampled on Days -1, 0, 1 and 2 from weaning. All 10 multiparous sows receiving LS + BE exhibited oestrus during lactation, whereas none of the 4 primiparous sows exposed to LS + BE or the 2 control multiparous and 2 control primiparous sows exhibited lactational oestrus. Overall concentrations of LH in serum were higher (P less than 0.05) in sows receiving LS + BE than in control sows during lactation, whereas overall FSH was higher (P less than 0.05) in primiparous than multiparous sows. Number and amplitude of pulses of LH were greater (P less than 0.05) for treated primiparous than multiparous sows during lactation. Oestradiol-17 beta increased (P less than 0.05) in sows during LS + BE and was higher (P less than 0.01) in multiparous sows of this group than control multiparous or treated primiparous sows. Preweaning concentrations of cortisol and progesterone in serum were higher (P less than 0.05) in treated than control sows for multiparous and primiparous animals. In sows resampled at weaning, the number of pulses of LH was greater (P less than 0.05) in treated primiparous than in control sows. Postweaning concentrations of FSH in serum were unaffected by preweaning treatments. It was concluded that (1) litter separation and boar exposure increased basal and pulsatile secretion of LH in multiparous and primiparous sows; (2) lack of ovarian follicular development and oestradiol secretion may preclude expression of oestrus in primiparous sows during lactation, despite elevated concentrations of FSH and LH in serum; and (3) if elevated concentrations of cortisol and progesterone inhibit the onset of oestrous cycles, in response to litter separation and boar exposure during lactation, the effect is limited to primiparous sows.  相似文献   
58.
Summary 5-enolpyruvylshikimate-3-phosphate synthase (EPSPs), the target of the herbicide glyphosate, catalyzes an essential step in the shikimate pathway common to aromatic amino acid biosynthesis. We have cloned an EPSP synthase gene from Arabidopsis thaliana by hybridization with a petunia cDNA probe. The Arabidopsis gene is highly homologous to the petunia gene within the mature enzyme but is only 23% homologous in the chloroplast transit peptide portion. The Arabidopsis gene contains seven introns in exactly the same positions as those in the petunia gene. The introns are, however, significantly smaller in the Arabidopsis gene. This reduction accounts for the significantly smaller size of the gene as compared to the petunia gene. We have fused the gene to the cauliflower mosaic virus 35 S promoter and reintroduced the chimeric gene into Arabidopsis. The resultant overproduction of EPSPs leads to glyphosate tolerance in transformed callus and plants.  相似文献   
59.
L G Perez  G L Davis    E Hunter 《Journal of virology》1987,61(10):2981-2988
The envelope glycoprotein complex of Rous sarcoma virus consists of a knoblike, receptor-binding gp85 polypeptide that is linked through disulfide bonds to a membrane-spanning gp37 spike. We used oligonucleotide-directed mutagenesis to assess the role of the hydrophobic transmembrane region and hydrophilic cytoplasmic domain of gp37 in intracellular transport and assembly into virions. Early termination codons were introduced on either side of the hydrophobic transmembrane region, and the mutated env genes were expressed from the late promoter of simian virus 40. This resulted in the synthesis of glycoprotein complexes composed of a normal gp85 and a truncated gp37 molecule that lacked the cytoplasmic domain alone or both the cytoplasmic and transmembrane domains. The biosynthesis and intracellular transport of the truncated proteins were not significantly different from those of the wild-type glycoproteins, suggesting that any protein signals for biosynthesis and intracellular transport of this viral glycoprotein complex must reside in its extracellular domain. The glycoprotein complex lacking the cytoplasmic domain of gp37 is stably expressed on the cell surface in a manner similar to that of the wild type. In contrast, the complex lacking both the transmembrane and cytoplasmic domains is secreted as a soluble molecule into the media. It can be concluded, therefore, that the transmembrane domain alone is essential for anchoring the RSV env complex in the cell membrane and that the cytoplasmic domain is not required for anchor function. Insertion of the mutated genes into an infectious proviral genome allowed us to assess the ability of the truncated gene products to be assembled into virions and to determine whether such virions were infectious. Viral genomes encoding the secreted glycoprotein were noninfectious, whereas those encoding a glycoprotein complex lacking only the cytoplasmic domain of gp37 were infectious. Virions produced from these mutant-infected cells contained normal levels of glycoprotein. The cytoplasmic tail of gp37 is thus not required for the assembly of envelope glycoproteins into virions. It is unlikely, therefore, that this region of gp37 interacts with viral core proteins during the selective incorporation of viral glycoproteins into the viral envelope.  相似文献   
60.
    
Summary Cloning of genes by transformation with genomic banks and rescue of a phenotype has been extensively used in bacterial systems. This approach has not been possible in plant systems because of the large genome sizes and poor transformation frequencies of most plant species. Recent advances in plant transformation permit the generation of large numbers of transformants in petunia. We have used this system to rescue a model gene encoding resistance to kanamycin by shotgun cloning. The gene encoding neomycin phosphotransferase (NPTII) was introduced into the genome of Arabidopsis thaliana by Agrobacterium tumefaciens-mediated transformation. A genomic bank of DNA from this tissue was constructed in a cosmid vector containing features which would allow its use in plant transformation. The unselected genomic bank was mobilized from Escherichia coli to A. tumefaciens and used to retransform petunia leaf discs. The rescued gene was identified by its ability to confer a kanamycin-resistant phenotype in petunia tissue. The presence of the NPTII gene was confirmed by nopaline assay and Southern blot analysis. This experiment demonstrates the feasibility of gene rescue, in certain circumstances, in plants.  相似文献   
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