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711.
Kong F Abe J Takahashi K Matsuura H Yoshihara T Nabeta K 《Biochemical and biophysical research communications》2005,336(4):1150-1156
Theobroxide, a natural product, strongly stimulates the biosynthesis of jasmonic acid (JA) in Pharbitis nil. In this study, we investigated the accumulation of protein by the immunoblot analysis of lipoxygenase (LOX), allene oxide synthase (AOS), and allene oxide cyclase (AOC), key enzymes in JA biosynthesis, and how the endogenous levels of JA in P. nil are affected by theobroxide. The effect of JA on the accumulations of these proteins was monitored simultaneously. The results show that theobroxide treatment led to a high level accumulation of JA, which is due to high accumulations of LOX, AOS, and AOC proteins induced by theobroxide treatment both under short day (SD) and long day (LD) conditions. However, under SD conditions AOS and AOC proteins are not enhanced by JA treatment. Kinetic analysis of protein levels shows that a biphasic activation of AOC protein by theobroxide is displayed and the first activation of AOC protein together with elevated JA levels is observed within 30min after treatment. Meanwhile, AOS and LOX proteins are activated by theobroxide later than AOC protein, suggesting that AOC plays an essential role in the initial JA formation induced by theobroxide. Since theobroxide-increased JA levels also show a biphasic manner similar to AOC activation and AOS, LOX proteins are activated later than AOC, and thus we propose a positive JA feedback regulation. Interestingly, AOS protein, which is also the enzyme for the biosynthesis of 9,10-ketol-octadecadienoic acid (KODA, a flowering inducing factor), accumulates markedly due to the simultaneous involvement of theobroxide and SD conditions, suggesting that AOS probably plays a role in flower bud formation in P. nil. 相似文献
712.
Juan C. Castilla Malva Uribe Nibaldo Bahamonde Marcela Clarke Ruth Desqueyroux-Faúndez Ismael Kong Hugo Moyano Nicolás Rozbaczylo Bernabé Santelices Claudio Valdovinos Patricio Zavala 《Biological invasions》2005,7(2):213-232
This article presents the first compilation of marine non-indigenous species (NIS) of algae and macro-invertebrates invading Chilean waters. A total of 32 cosmopolitan and non-cosmopolitan species are reported. Among them there are six species considered as extending their southern range of distribution in connection with El Niño events. The article highlights negative and positive impacts caused by marine NIS invasions. Among the first are Codium fragile var. tomentosoide, considered as a pest in Gracilaria chilensis aquaculture facilities in northern Chile, and Ciona intestinalis, a pest in scallop aquaculture installations. Among the second are bio-engineers species, such as the ascidian Pyura praeputialis and the sea grass Heterozostera tasmanica, which have caused an increase in local biodiversity and enhancement of nursery grounds via the creation of new habitats. Further more, invaders such as the algae Mastocarpus papillosus, Porphyra linearis and P. pseudolinearis represent new exploitable resources, extracted by coastal food gatherers along the coast (M. papillosus) or potential species to develop aquaculture. Additional information is presented on the anemone Anemonia alicemartinae, which appears to be a native species (?), having shown in the past 40–50 years, a geographical southward range extension of approximately 1900 km. The number of NIS reported for Chile is compared with those published for the southwestern Atlantic, South Africa, North America (Atlantic and Pacific coasts) and New Zealand. It is suggested that probably the low number of Chilean NIS is due to the fact that the Chilean coasts are environmentally less stressed than other coasts in the world, due to the scarcity of estuaries, gulfs, enclosed bays, lagoons and low human populations. These kinds of sheltered areas have been suggested as centers for bio-invasions, due to the high rate of human-mediated transfer and increase of pollutants. Furthermore, none of NIS reported from Chile show a fast geographical expansion rate (exception of A. alicemartinae), nor invading strategies such as those described for marine NIS in other latitudes, where notorious ecological unbalances following invasions have been observed. An alternative hypothesis is that the low number of marine NIS invading Chile is underestimated, since the modern list of species generated through specific taxonomically intensive port and harbor surveys is still lacking. Fifteen species (five invertebrate and 10 fish) have been deliberately imported to Chile for aquaculture. The invertebrates appear to be controlled within aquaculture facilities and have not established naturalized populations or caused direct ecological impacts on local communities. On the contrary, several millions of salmoniforms (and rainbow trout) have escaped from farming facilities in southern Chile and established naturalized populations. Studies on ecological impacts are lacking. These escapees are also playing a role in the enhancement of artisanal and sport fishery activities. 相似文献
713.
Strategy for allosteric analysis based on protein-patterned stationary phase in microfluidic chip 总被引:2,自引:0,他引:2
An effective method is presented for the on-chip analysis of chiral interactions with a successful depression of nonspecific adsorption. The alumina gel-derived protein network on poly(methyl methacrylate) (PMMA) microchannel was explored to form a protein-stationary phase and then used to carry out electrophoresis for fast enantioseparation coupled with electrochemical detection. On the basis of the chemical modification of a synthesized copolymer containing silane-functionalized scaffold, alumina sol-gel could react readily with the silane groups and form steady microstructure on the chip surface achieving the encapsulation of functional biomolecules. Compared with the native PMMA microchannels, the modified surfaces exhibited much better wettability, more stable and enhanced electroosmotic mobility, and less nonspecific adsorption. The water contact angle and EOF of alumina-gel-derived PMMA substrate were 22 degrees and 4.3 x 10(-4) cm(2) V(-1) s(-1), compared to those of 73 degrees and 1.9 x 10(-4) cm(2) V(-1) s(-1) from the untreated one, respectively. Bovine serum albumin, acting as a target protein, could be stably and homogeneously immobilized in the modified PMMA microchannel to fabricate a protein-stationary phase. Under a mild condition, D- and L-tryptophan were efficiently separated with a resolution of 1.57. The as-prepared microchip can perform chiral separations within short time, indicating that the general protocol has the potential to provide a platform for high throughput screening of enantiomer candidates such as those biochemical drugs with protein targets and the research of receptor interactions. 相似文献
714.
Jiang AL Zhang PJ Hu XY Chen WW Kong F Liu ZF Yuan HQ Zhang JY 《Acta biochimica et biophysica Sinica》2005,37(11):773-778
NKX3.1 is a prostate-specific homeobox gene related to prostate development and prostate cancer. In this work, we aimed to identify precisely the functional cis-element in the 197 bp region (from -1032 to -836 bp) of the NKX3.1 promoter (from -1032 to +8 bp), which was previously identified to present positive regulatory activity on NKX3.1 expression, by deletion mutagenesis analysis and electrophoretic mobility shift assay (EMSA). A 16 bp positive cis-element located between -920 and -905 bp upstream of the NKX3.1 gene was identified by deletion mutation analysis and proved to be a functional positive cis-element by EMSA. It will be important to further study the functions and regulatory mechanisms of this positive cis-element in NKX3.1 gene expression. 相似文献
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Bayesian experimental design is investigated for Bayesian analysis of nonlinear mixed-effects models. Existence of the posterior risk for parameter estimation is shown. When the same prior distribution is used for both design and inference, existence of the preposterior risk for design is also proven. If the prior distribution used in design is different from that used for inference, sufficient conditions are established for existence of the preposterior risk for design. A case study of design for an experiment in population HIV dynamics is provided. 相似文献
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719.
720.
OBJECTIVE: To describe the cytomorphologic features of nodular fasciitis that differentiate it from schwannoma. STUDY DESIGN: The cytomorphologic features of 10 cases of nodular fasciitis were compared to those of 4 cases of biopsy-proven schwannoma. Aspirate smears were evaluated for cellular cohesion, cell type and stroma. Immunoperoxidase stains were utilized in select cases. RESULTS: The cases of nodular fasciitis exhibited cohesive clusters of epithelioid to spindle-shaped cells in a background of single, intact mesenchymal cells; inflammatory cells; and myxoid stroma. In contrast, schwannomas lacked single, intact cells and inflammation. Schwannoma stroma was also myxoid but appeared more finely fibrillar, and cell clusters were notable for alternating areas of hypercellularity and hypocellularity. Immunoperoxidase stains demonstrated smooth muscle actin reactivity in 5 cases of nodular fasciitis and S-100 in 2 cases of schwannoma. CONCLUSION: Nodular fasciitis can be distinguished from schwannomas on the basis of cytomorphologic features and immunocytochemical profile. Cytologic diagnosis of nodular fasciitis is important since it obviates the need for surgical excision. 相似文献