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181.
Viana R Towler MC Pan DA Carling D Viollet B Hardie DG Sanz P 《The Journal of biological chemistry》2007,282(22):16117-16125
Mammalian AMP-activated protein kinase is a serine/threonine protein kinase that acts as a sensor of cellular energy status. AMP-activated protein kinase is a heterotrimer of three different subunits, i.e. alpha, beta, and gamma, with alpha being the catalytic subunit and beta and gamma having regulatory roles. Although several studies have defined different domains in alpha and beta involved in the interaction with the other subunits of the complex, little is known about the regions of the gamma subunits involved in these interactions. To study this, we have made sequential deletions from the N termini of the gamma subunit isoforms and studied the interactions with alpha and beta subunits, both by two-hybrid analysis and by co-immunoprecipitation. Our results suggest that a conserved region of 20-25 amino acids in gamma1, gamma2, and gamma3, immediately N-terminal to the Bateman domains, is required for the formation of a functional, active alphabetagamma complex. This region is required for the interaction with the beta subunits. The interaction between the alpha and gamma subunits does not require this region and occurs instead within the Bateman domains of the gamma subunit, although the alpha-gamma interaction does appear to stabilize the beta-gamma interaction. In addition, sequential deletions from the C termini of the gamma subunits indicate that deletion of any of the CBS (cystathionine beta-synthase) motifs prevents the formation of a functional complex with the alpha and beta subunits. 相似文献
182.
Li S Sang S Pan MH Lai CS Lo CY Yang CS Ho CT 《Bioorganic & medicinal chemistry letters》2007,17(18):5177-5181
Nobiletin, a major component of polymethoxyflavones in citrus fruits, has a broad spectrum of health beneficial properties including anti-inflammatory and anti-carcinogenic activities. The metabolite identification of nobiletin in mouse urine has concluded that it undergoes mono-demethylation (3'- and 4'-demethylnobiletin) and di-demethylation (3',4'-didemethylnobiletin) metabolic pathway. Biological screening of nobiletin and its metabolites has revealed that the metabolites possess more potent anti-inflammatory activity than their parent compound. Therefore, this letter reports the identification of nobiletin metabolites and their anti-inflammatory activity against LPS-induced NO production and iNOS, COX-2 protein expression in RAW264.7 macrophage. 相似文献
183.
Many clinical trials compare two or more treatment groups by using a binary outcome measure. For example, the goal could be to determine whether the frequency of pain episodes is significantly reduced in the treatment group (arm A) as compared to the control group (arm B). However, for ethical or regulatory reasons, group sequential designs are commonly employed. Then, based on a binomial distribution, the stopping boundaries for the interim analyses are constructed for assessing the difference in the response probabilities between the two groups. This is easily accomplished by using any of the standard procedures, e.g., those discussed by Jennison and Turnbull (2000), and using one of the most commonly used software packages, East (2000). Several factors are known to often affect the primary outcome of interest, but their true distributions are not known in advance. In addition, these factors may cause heterogeneous treatment responses among individuals in a group, and their exact effect size may be unknown. To limit the effect of such factors on the comparison of the two arms, stratified randomization is used in the actual conduct of the trial. Then, a stratified analysis based on the odds ratio proposed in Jennison and Turnbull (2000, pages 251-252) and consistent with the stratified design is undertaken. However, the stopping rules used for the interim analyses are those obtained for determining the differences in response rates in a design that was not stratified. The purpose of this paper is to assess the robustness of such an approach on the performance of the odds ratio test when the underlying distribution and effect size of the factors that influence the outcome may vary. The simulation studies indicate that, in general, the stratified approach offers consistently better results than does the unstratified approach, as long as the difference in the weighted average of the response probabilities across strata between the two groups remains closer to the hypothesized values, irrespective of the differences in the (allocation) distributions and heterogeneous response rate. However, if the response probabilities deviate significantly from the hypothesized values so that the difference in the weighted average is less than the hypothesized value, then the proposed study could be significantly underpowered. 相似文献
184.
185.
Inactivation of the cyclic nucleotide signal in granulosa cells depends on a complex array of cyclic nucleotide phosphodiesterases (PDE). In order to examine the role of PDE in cyclic AMP (cAMP) signaling in granulosa cells, the present study examined the expression of PDE4D proteins and regulation of cAMP-PDE activities in cultured rat granulosa cells. The results of immunoblot analyses showed that two predominant PDE4D subtypes of approximately 80 and 70 kDa appeared when immature rat granulosa cells were treated with FSH. However, these two new subtypes presumed to be PDE4D proteins were not influenced by treatments of DETA/NO, cGMP and PKB inhibitor, LY294002. Immature rat granulosa cells treated with medium alone displayed low cAMP-PDE activity throughout 48 h of culture while those treated with FSH (2 ng.mL-1) showed a marked increase in cAMP-PDE activity between 6 and 12 h of culture, followed by a decline. The findings from the present study indicate that the increased cAMP-PDE activity by FSH is mainly related to the changes of PDE4D protein levels. However, the inhibitory effects of NO on cAMP accumulation in rat granulosa cells are not via the increased cAMP-PDE activity. 相似文献
186.
187.
Bedelbaeva K Gourevitch D Clark L Chen P Leferovich JM Heber-Katz E 《Cloning and stem cells》2004,6(4):352-363
We previously demonstrated that after a severe cryoinjury to the right ventricle of the heart, adult MRL mice display structural and functional recovery with myocardial tissue replacement resembling that seen in amphibians. The control non-regenerating adult C57BL/6 (B6) mouse shows a predominant scar response. In the present study, radiation chimeras reconstituted with fetal liver cells from either healer MRL or nonhealer B6 mice were generated to test for a transfer of phenotype. Allogeneic MRL fetal liver cells were injected into x-irradiated (9 Gy) B6 mice and B6 fetal liver cells were injected into x-irradiated MRL mice. In these allogeneic chimeras, the healing response to cardiac cryoinjury was predominantly of the donor phenotype. Thus, MRL fetal liver cells transferred the healing phenotype to the B6 nonhealer with the appearance of Y-chromosome positive, donor-derived cardiomyocytes in the injury site and MRL-like healing with little scar. Similarly, B6 fetal liver cells transferred the nonhealing phenotype to the MRL with little cardiomyocyte growth and an acellular B6-like scar. These results are in contrast to the ear hole closure response which was of the recipient phenotype. We conclude that, in the case of the heart, fetal liver-derived stem cells regulate regenerative healing. 相似文献
188.
Li YZ Pan YH Sun CB Dong HT Luo XL Wang ZQ Tang JL Chen B 《Plant molecular biology》2010,74(6):573-590
A cDNA library was constructed from the root tissues of cassava variety Huanan 124 at the root bulking stage. A total of 9,600
cDNA clones from the library were sequenced with single-pass from the 5′-terminus to establish a catalogue of expressed sequence
tags (ESTs). Assembly of the resulting EST sequences resulted in 2,878 putative unigenes. Blastn analysis showed that 62.6%
of the unigenes matched with known cassava ESTs and the rest had no ‘hits’ against the cassava database in the integrative
PlantGDB database. Blastx analysis showed that 1,715 (59.59%) of the unigenes matched with one or more GenBank protein entries
and 1,163 (40.41%) had no ‘hits’. A cDNA microarray with 2,878 unigenes was developed and used to analyze gene expression
profiling of Huanan 124 at key growth stages including seedling, formation of root system, root bulking, and starch maturity.
Array data analysis revealed that (1) the higher ratio of up-regulated ribosome-related genes was accompanied by a high ratio
of up-regulated ubiquitin, proteasome-related and protease genes in cassava roots; (2) starch formation and degradation simultaneously
occur at the early stages of root development but starch degradation is declined partially due to decrease in UDP-glucose
dehydrogenase activity with root maturity; (3) starch may also be synthesized in situ in roots; (4) starch synthesis, translocation,
and accumulation are also associated probably with signaling pathways that parallel Wnt, LAM, TCS and ErbB signaling pathways
in animals; (5) constitutive expression of stress-responsive genes may be due to the adaptation of cassava to harsh environments
during long-term evolution. 相似文献
189.
This article provides the analysis on biomass yields and energetic yields of the oleaginous yeasts. The biomass yields of the oleaginous yeasts are consistently lower than nonoleaginous microorganisms, whereas their energetic yields are higher. Data inconsistencies of literature are explained by the variation of energy contents of oleaginous yeasts. 相似文献
190.
The taxonomical concept of the Paeonia suffruticosa complex i.e. Sect. Moutan Subsect. Vaginatae, has changed greatly since 1990. Six species and four subspecies have been described as new and two subspecies raised to specific level. Five species and two subspecies are recognized in the present revision, viz. P. suffruticosa subsp. suffruticosa and subsp. yinpingmudan, P. jishanensis, P. qiui, P. ostii, P. rockii subsp. rockii and subsp. taibaishanica. P. yananensis, P. ridleyi, P. spontanea, P. moutan subsp. atava, P. suffruticosa subsp. atava, P. rockii subsp. linyanshanii and P. ostii var. lishizhenii are treated as synonyms. P. papaveracea and P. baokangensis are proposed to be interspecific hybrids. A key to the recognized species and subspecies is provided. Biological features of the species are described and their distributions are mapped. The relationships between species are inferred and the origins of commonly cultivated tree peonies ( P. suffruticosa and P. ostii ) are discussed. 相似文献