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11.
A H Hale  M J Weber 《Cell》1975,5(3):245-252
We have asked whether treatment of normal cultured cells with proteases, other hydrolytic enzymes, or serum can convert them into transient phenocopies of transformed cells with respect to the very high rate of hexose transport characteristic of transformed cells. Treatment of density-inhibited cultures of normal chick embryo fibroblasts with trypsin, plasmin, neuraminidase, or hyaluronidase stimulated their rate of 2-deoxyglucose uptake to a level only marginally higher than that seen in normal exponentially growing cultures, and only 35-45% of that seen in transformed cultures. Addition of the hydrolytic enzymes to growing cell cultures had little effect on 2-deoxyglucose uptake. Serum, however, could stimulate 2-deoxyglucose uptake all the way up to the transformed level. Even though the hydrolases and serum differed in their ability to stimulate 2-deoxyglucose uptake, both reagents were capable of stimulating cell division equally well. Evidence is presented suggesting that the hexose transport rate is controlled by serum factors, and that proteolysis can affect the response of the cells of these factors.  相似文献   
12.
The efficacy of intravenous Prostaglandin F (PGF) infusion for induction of labor in two different dosage schedules was studied in 90 women between 36 and 43 weeks of gestation. The rate of PGF infusion was increased at four-hour intervals in 36 women in the low dosage group and every hour in 54 women in the high dosage group, never exceeding an infusion rate of 20 μg/min. in either group. Labor was successfully induced in approximately 90% of the patients in each group. There was no statistically significant difference in the mean induction-delivery interval between the two groups at the 5 percent level. Intravenous PGF was found to be effective and safe for both mother and infant in the dosage schedules used in this study for induction of labor.  相似文献   
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14.
Survivin as a target for new anticancer interventions   总被引:66,自引:0,他引:66  
Survivin is a member of the inhibitor of apoptosis protein (IAP) family, that has been implicated in both control of cell division and inhibition of apoptosis. Specifically, its anti-apoptotic function seems to be related to the ability to directly or indirectly inhibit caspases. Survivin is selectively expressed in the most common human neoplasms and appears to be involved in tumor cell resistance to some anticancer agents and ionizing radiation. On the basis of these findings survivin has been proposed as an attractive target for new anticancer interventions. Several preclinical studies have demonstrated that down-regulation of survivin expression/function, accomplished through the use of antisense oligonucleotides, dominant negative mutants, ribozymes, small interfering RNAs and cyclin-dependent kinase inhibitors, increased the apoptotic rate, reduced tumor-growth potential and sensitized tumor cells to chemotherapeutic drugs with different action mechanisms and gamma-irradiation in in vitro and in vivo models of different human tumor types.  相似文献   
15.
Representatives from agencies involved in natural resource management in the Murray‐Darling Basin gathered for a workshop in November 2010 to develop a vision for improved monitoring and reporting of riparian restoration projects. The resounding message from this workshop was that the effectiveness of riparian restoration depends on having sound, documented and agreed evidence on the ecological responses to restoration efforts. Improving our capacity to manage and restore riparian ecosystems is constrained by (i) a lack of ecological evidence on the effects of restoration efforts, and (ii) short‐termism in commitment to restoration efforts, in funding of monitoring and in expected time spans for ecosystem recovery. Restoration at the effective spatial scope will invariably require a long‐term commitment by researchers, funding agencies, management agencies and landholders. To address the knowledge gaps that constrain riparian restoration in the Basin, participants endorsed four major fields for future research: the importance of landscape context to restoration outcomes; spatio‐temporal scaling of restoration outcomes; functional effects of restoration efforts; and developing informative and effective indicators of restoration. To improve the monitoring and restoration of riparian zones throughout the Basin, participants advocated an integrated approach: a hierarchical adaptive management framework that incorporates long‐term ecological research.  相似文献   
16.
Chemical proteomics is an emerging technique for drug target deconvolution and profiling the toxicity of known drugs. With the use of this technique, the specificity of a small molecule inhibitor toward its potential targets can be characterized and information thus obtained can be used in optimizing lead compounds. Most commonly, small molecules are immobilized on solid supports and used as affinity chromatography resins to bind targets. However, it is difficult to evaluate the effect of immobilization on the affinity of the compounds to their targets. Here, we describe the development and application of a soluble probe where a small molecule was coupled with a peptide epitope which was used to affinity isolate binding proteins from cell lysate. The soluble probe allowed direct verification that the compound after coupling with peptide epitope retained its binding characteristics. The PKC-alpha inhibitor Bisindolylmaleimide-III was coupled with a peptide containing the FLAG epitope. Following incubation with cellular lysates, the compound and associated proteins were affinity isolated using anti-FLAG antibody beads. Using this approach, we identified the known Bisindolylmaleimide-III targets, PKC-alpha, GSK3-beta, CaMKII, adenosine kinase, CDK2, and quinine reductase type 2, as well as previously unidentified targets PKAC-alpha, prohibitin, VDAC and heme binding proteins. This method was directly compared to the solid-phase method (small molecule was immobilized to a solid support) providing an orthogonal strategy to aid in target deconvolution and help to eliminate false positives originating from nonspecific binding of the proteins to the matrix.  相似文献   
17.
β-Pinene, an oxygenated monoterpene, is one of the major monoterpenes emitted into the atmosphere from forest areas and trees. Besides, it is a principal component of essential oils of a number of aromatic plants, which are involved in a variety of ecological interactions, including allelopathy, in the natural environment. However, studies pertaining to phytotoxicity and biochemical effect(s) of β-pinene are largely lacking. We investigated the effect of β-pinene (0.02, 0.04, 0.08, 0.20, 0.40 and 0.80 mg/ml) in a dose- and time-dependent manner on early seedling growth, dry weight accumulation, photosynthetic pigments and changes in macromolecule (protein and carbohydrate) content and activities of enzymes—proteases, α- and β-amylases, polyphenol oxidases and peroxidases- in rice (Oryza sativa) after 3rd, 5th and 7th day of exposure. β-pinene (≥0.04 mg/ml) significantly reduced the root (by 13–87%) and coleoptile (by 5–80%) length of rice. Exposure to β-pinene reduced total chlorophyll content in rice coleoptiles suggesting a negative impact on photosynthesis. The content of macromolecules (proteins and carbohydrates) enhanced significantly in response to β-pinene, whereas the activities of hydrolyzing enzymes—proteases, α-amylases, and β-amylases—declined (by 30–85, 26–84, 27–74%, respectively) in β-pinene-exposed seedlings. In contrast, the activities of peroxidases (POX) and polyphenol oxidases (PPO) enhanced significantly (by 16–152 and 53–290%, respectively) in rice roots in response to β-pinene in a dose- and time-dependent manner. Increased activities of POX and PPO indicate their involvement in providing protection and/or conferring resistance against β-pinene-induced stress. The study concludes that β-pinene inhibits the early growth of rice by altering the plant biochemical status and enhancing activities of POXs and PPOs involved in general plant defense.  相似文献   
18.
Antimicrobial peptides (AMPs) appear as chemical compounds of increasing interest for their role in killing bacteria and, more recently, for their ability to bind endotoxin (lipopolysaccharide, LPS) that is released during bacterial infection and that may lead to septic shock. This dual role in the mechanism of action can further be enhanced in a synergistic way when two or more AMPs are combined together. Not all AMPs are able to bind LPS, suggesting that several modes of binding to the bacterial surface may exist. Here we analyze a natural AMP, crabrolin, and two mutated forms, one with increased positive charge (Crabrolin Plus) and the other with null charge (Crabrolin Minus), and compare their binding abilities to LPS. While Crabrolin WT as well Crabrolin Minus do not show binding to LPS, the mutated Crabrolin Plus exhibits binding and forms a well defined structure in the presence of LPS. The results strengthen the importance of positive charges for the binding to LPS and suggest the mutated form with increased positive charge as a promising candidate for antimicrobial and antiseptic activity.  相似文献   
19.
The European hazelnut (Corylus avellana L.) is the most economically important nut species in the Betulaceae family. Despite the need for new improved hazelnut cultivars, few breeding programs are carried out because of the large plant size, the long lifecycle of the plant, and the expense and time required. To date, there are no reports of maps with quantitative trait loci (QTL) in hazelnut. Our objective in the present study was to identify QTL associated with vegetative traits to allow marker-assisted selection (MAS). An F1 progeny (275 plants) of Tonda Gentile delle Langhe × Merveille de Bollwiller obtained in 2009 was used to develop a QTL linkage map for vigour, sucker habit, and time of bud burst, after three years of observations. A set of 163 plants were analysed with 152 microsatellite markers. A map of 11 linkage groups was obtained, covering 663.1 cM, and 15 QTLs were identified and mapped for the traits examined. Of them, 10 were ‘major’ QTL, including a stably expressed region on LG_02 for leaf bud burst. At least one major QTL for each year underlies the variation in each trait and a clustering of QTL for trunk circumference and suckers/trunk circumference ratio with high inter-trait correlations was observed on LG_05, suggesting a single pleiotropic locus. This research represents an initial step in the future identification of chromosomal regions carrying genes of interest, important for breeding programs and MAS.  相似文献   
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