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排序方式: 共有71条查询结果,搜索用时 46 毫秒
61.
Marcelo Filonzi Laís C Cardoso Maristela T Pimenta Daniel BC Queiróz Maria CW Avellar Catarina S Porto Maria FM Lazari 《Reproductive biology and endocrinology : RB&E》2007,5(1):29
Background
Relaxin is the endogenous ligand of the G-protein coupled receptor RXFP1, previously known as LGR7. In humans relaxin can also activate, but with lower affinity, the closely related receptor for the insulin-like peptide from Leydig cells, RXFP2, previously known as LGR8. The lack of relaxin impairs male fertility but the precise distribution and the function of relaxin receptors in the male reproductive tract is not known. We investigated the distribution of Rxfp1 and Rxfp2 in the reproductive tract of the male rat and the function of relaxin in the vas deferens, a tissue with high expression of both receptors. 相似文献62.
Friedman DB Wang SE Whitwell CW Caprioli RM Arteaga CL 《Molecular & cellular proteomics : MCP》2007,6(1):150-169
Multivariable DIGE/MS was used to investigate proteins altered in expression and/or post-translational modification in response to activation of transforming growth factor (TGF)-beta receptors in MCF10A mammary epithelial cells overexpressing the HER2/Neu (ErbB2) oncogene. Proteome changes were monitored in response to exogenous TGF-beta over time (0, 8, 24, and 40 h), and proteins were resolved using medium range (pH 4-7) and narrow range (pH 5.3-6.5) isoelectric focusing combined with up to 2 mg of protein to allow inspection of lower abundance proteins. Triplicate samples were prepared independently and analyzed together across multiple DIGE gels using a pooled sample internal standard to quantify expression changes with statistical confidence. Unsupervised principle component analysis and hierarchical clustering of the individual DIGE proteome expression maps provided independent confirmation of distinct expression patterns from the individual experiments and demonstrated high reproducibility between replicate samples. Fifty-nine proteins (including some isoforms) that exhibited significant kinetic expression changes were identified using mass spectrometry and database interrogation and were mapped to existing biological networks involved in TGF-beta signaling. Several proteins with a potential role in breast cancer, such as maspin and cathepsin D, were identified as novel molecules associated with TGF-beta signaling. 相似文献
63.
A cDNA molecule encoding a major part of the human Norepinephrine transporter(hNET) was synthesized by means of Polymerase Chain Reaction(PCR) technique and used as a probe for selecting the human genomic NET gene.A positive clone harbouring the whole gene was obtained from a human lymphocyte genomic library through utilizing the “genomic walking” technique.The clone,designated as phNET,harbours a DNA fragment of about 59 kd in length inserted into BamH I site in cosmid pWE15.The genomic clone contains 14 exons encoding all amino acid residues in the protein.A single exon encodes a distinct transmembrane domain,except for transmembrane domain 10 and 11,which are encoded by part of two exons respectively,and exon 12,which encodes part of domain 11 and all of domain 12.These results imply that there is a close relationship between exon splicing of a gene and structureal domains of the protein,as is the case for the human γ-aminobutyric acid transporter(hGAT) and a number of other membrane proteins. 相似文献
64.
The effect of relaxed functional constraints on the photosynthetic gene rbcL in photosynthetic and nonphotosynthetic parasitic plants 总被引:1,自引:0,他引:1
The photosynthetic gene rbcL has been lost or dramatically altered in some
lineages of nonphotosynthetic parasitic plants, but the dynamics of these
events following loss of photosynthesis and whether rbcL has sustained
functionally significant changes in photosynthetic parasitic plants are
unknown. To assess the changes to rbcL associated with the loss of
functional constraints for photosynthesis, nucleotide sequences from
nonparasitic and parasitic plants of Scrophulariales were used for
phylogeny reconstruction and character analysis. Plants in this group
display a broad range of parasitic abilities, from photosynthetic
("hemiparasites") to nonphotosynthetic ("holoparasites"). With the
exception of Conopholis (Orobanchaceae), the rbcL locus is present in all
parasitic plants of Scrophulariales examined. Several holoparasitic genera
included in this study, including Boschniakia, Epifagus, Orobanche, and
Hyobanche, have rbcL pseudogenes. However, the holoparasites Alectra
orobanchoides, Harveya capensis, Harveya purpurea, Lathraea clandestina,
Orobanche corymbosa, O. fasciculata, and Striga gesnerioides have intact
open reading frames (ORFs) for the rbcL gene. Phylogenetic hypotheses based
on rbcL are largely in agreement with those based on sequences of the
nonphotosynthetic genes rps2 and matK and show a single origin of
parasitism, and loss of photosynthesis and pseudogene formation have been
independently derived several times in Scrophulariales. The mutations in
rbcL in nonparasitic and hemiparasitic plants would result in largely
conservative amino acid substitutions, supporting the hypothesis that
functional proteins can experience only a limited range of changes, even in
minimally photosynthetic plants. In contrast, ORFs in some holoparasites
had many previously unobserved missense substitutions at functionally
important amino acid residues, suggesting that rbcL genes in these plants
have evolved under relaxed or altered functional constraints.
相似文献
65.
Positive genotoxicity results are often observed using mammalian cells in culture with agents that are not in vivo genotoxins. We here illustrate one possible explanation: interaction of test chemicals with the cell-culture media used. We find that the toxicity and clastogenicity of epigallocatechin gallate (EGCG) to Chinese Hamster ovary (CHO) cells is affected by the culture medium used and appears largely or entirely due to variable rates of formation of hydrogen peroxide (H(2)O(2)) by chemical reactions of EGCG with the culture media. Catalase decreased EGCG toxicity substantially. Of seven different types of commonly used media evaluated, F-10 and F-12 nutrient mixtures were the least prone to produce this artefact. Although it generated H(2)O(2) in the culture media, ascorbate was not toxic to CHO cells because the H(2)O(2) levels achieved were insufficient to kill these cells. Thus, the culture medium, the cell type and the presence or absence of catalase (e.g. its variable amounts in S9 fractions) must be taken into account in in vitro genotoxicity testing. 相似文献
66.
67.
Sumaiyya Thawer Jennifer Auret Corinna Schnoeller Alisha Chetty Katherine Smith Matthew Darby Luke Roberts Rosie-Marie Mackay Harry J. Whitwell John F. Timms Jens Madsen Murray E. Selkirk Frank Brombacher Howard William Clark William G. C. Horsnell 《PLoS pathogens》2016,12(2)
Pulmonary epithelial cell responses can enhance type 2 immunity and contribute to control of nematode infections. An important epithelial product is the collectin Surfactant Protein D (SP-D). We found that SP-D concentrations increased in the lung following Nippostrongylus brasiliensis infection; this increase was dependent on key components of the type 2 immune response. We carried out loss and gain of function studies of SP-D to establish if SP-D was required for optimal immunity to the parasite. N. brasiliensis infection of SP-D-/- mice resulted in profound impairment of host innate immunity and ability to resolve infection. Raising pulmonary SP-D levels prior to infection enhanced parasite expulsion and type 2 immune responses, including increased numbers of IL-13 producing type 2 innate lymphoid cells (ILC2), elevated expression of markers of alternative activation by alveolar macrophages (alvM) and increased production of the type 2 cytokines IL-4 and IL-13. Adoptive transfer of alvM from SP-D-treated parasite infected mice into naïve recipients enhanced immunity to N. brasiliensis. Protection was associated with selective binding by the SP-D carbohydrate recognition domain (CRD) to L4 parasites to enhance their killing by alvM. These findings are the first demonstration that the collectin SP-D is an essential component of host innate immunity to helminths. 相似文献
68.
Mark WEJ Fiers Ate van der Burgt Erwin Datema Joost CW de Groot Roeland CHJ van Ham 《BMC bioinformatics》2008,9(1):96
Background
Modern omics research involves the application of high-throughput technologies that generate vast volumes of data. These data need to be pre-processed, analyzed and integrated with existing knowledge through the use of diverse sets of software tools, models and databases. The analyses are often interdependent and chained together to form complex workflows or pipelines. Given the volume of the data used and the multitude of computational resources available, specialized pipeline software is required to make high-throughput analysis of large-scale omics datasets feasible. 相似文献69.
Warran G. Abrahamson Kenneth D. McCrea Amy J. Whitwell Laurie A. Vernieri 《Biochemical Systematics and Ecology》1991,19(8):615-622
Some genotypes of Solidago altissima have been shown to exhibit a hypersensitive response to the tephritid ball gallmaker Eurosta solidaginis. When the gallmaker attempts to stimulate gall formation in these genotypes, necrotic tissue surrounds the larva and apparently causes larval death [Anderson, S. S., et al. (1989) Ecology 70, 1048]. Other genotypes have varying degrees of resistance or susceptibility [McCrea, K. D. and Abrahamson, W. G. (1987) Ecology 68, 822]. Studies of other host plants have shown that phenolic compounds can play an important role in this defensive reaction. To determine the role of phenolics in the resistance of S. altissima to ball gallmakers, weekly tissue samples were collected from two resistant and two susceptible clones, both with and without Eurosta attack. These samples were analysed for total phenolics using the Folin-Ciocalteau procedure. Phenolic content increased over time in all clones. In unattacked ramets, phenolic levels were higher in susceptible clones than in resistant clones. No evidence of an increase in phenolics was seen with a hypersensitive response, but a significantly higher concentration was found in plants that had initiated normal gall development. A second study of rapidly growing galls in three additional susceptible clones confirmed this increase in phenolics, demontrated that the higher phenolic concentrations were restricted to gall tissue, and showed that phenolic levels increase as much as five-fold in galls near their peak growth period. Increases in total phenolic levels were clearly not responsible for the hypersensitive reaction for resistance, but phenols could potentially play a role in gall formation by influencing the hormonal control of growth and/or in protection of the gallmaker from its natural enemies. 相似文献
70.
James R. Whitwell 《BMJ (Clinical research ed.)》1922,2(3219):490-491