752 research outputs found

    The distribution of distinct integrins in focal contacts is determined by the substratum composition

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    The distribution of two integrins, the fibronectin receptor and the vitronectin receptor, has been explored in an endothelium-derived cell line plated onto various substrata. On a fibronectin substratum, in the presence of serum, these cells develop focal contacts that contain the fibronectin receptor, whereas the vitronectin receptor is diffusely distributed over the cell surface. Conversely, cells plated onto vitronectin-coated coverslips concentrate only the vitronectin receptor within focal contacts. The accumulation of the vitronectin receptor within focal contacts also occurs when the cells are plated on uncoated coverslips but in the presence of serum. Therefore, we conclude that under normal culture conditions (i.e. in serum-containing media), the vitronectin receptor is the predominant form of integrin involved in substratum adhesion. This conclusion is supported by experiments in which cells were cultured on fibronectin-coated coverslips in the presence of serum. Initially these cells developed focal contacts containing only the fibronectin receptor. Within several hours, however, there was a progressive replacement of focal contacts containing the fibronectin receptor by focal contacts expressing the vitronectin receptor. After approximately 12 h in culture, most cells contained focal contacts expressing only the vitronectin receptor. Focal contacts containing either the fibronectin or vitronectin receptor were both associated with the termini of stress fibres and contained the proteins talin and vinculin. These observations lead us to propose that the cell does not discriminate between these different integrins when assembling the cytoskeletal components at the cytoplasmic face of focal contacts

    Specific cleavage analysis of mammalian mitochondrial DNA.

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    Two mouse early embryonic beta-globin gene sequences. Evolution of the nonadult beta-globins.

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    We have determined the complete nucleotide sequence of two early embryonic beta-globin genes of the BALB/c mouse: beta h0 and beta h1 X beta h1 codes for the embryonic z protein, while the beta h0 gene may be a minor early embryonic beta-globin gene. The general sequence organization of both genes is entirely analogous to other functional globin genes. There is, however, a 220-base pair insertion of unique sequence within the first intron of beta h0 X beta h0 and beta h1 are 96% homologous for 260 base pairs 5' to the AUG initiation codon, and 93% homologous throughout their coding regions. Analysis of the 5'-flanking sequence demonstrates that these genes are more nonadult-like than adult-like. The sequences show evidence for gene conversions among the mouse nonadult beta-globin genes that were limited to individual exons, presumably by the presence of non-homologous introns. We propose that this arrangement has the beneficial evolutionary effect of allowing gene conversion to act independently on regions of the protein with different structural or functional responsibilities. beta h0 and beta h1 are evolutionary homologs to the human fetal and rabbit beta 3 genes, while their manner of expression is similar to rabbit beta 3 and dissimilar to human fetal expression. The evolutionary history of the human beta-globin genes, therefore, includes the recruitment of an embryonic gene to fetal developmental control

    Permanent cell line expressing human factor VIII-related antigen established by hybridization.

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    A permanent human cell line, EA . hy 926, has been established that expresses at least one highly differentiated function of vascular endothelium, factor VIII-related antigen. This line was derived by fusing human umbilical vein endothelial cells with the permanent human cell line A549. Hybrid cells that survived in selective medium had more chromosomes than either progenitor cell type and included a marker chromosome from the A549 line. Factor VIII-related antigen can be identified intracellularly in the hybrids by immunofluorescence and accumulates in the culture fluid. Expression of factor VIII-related antigen by these hybrid cells has been maintained for more than 100 cumulative population doublings, including more than 50 passages and three cloning steps. This is evidence that EA . hy 926 represents a permanent line

    The diagonal-traverse homology search algorithm for locating similarities between two sequences

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    We present a fast computer algorithm for finding homology between two DNA sequences. It generates a two-dimensional display in which a diagonal string of dots represents a stretch of homology between the two sequences. Our algorithm performs the search very rapidly, and has no internal data storage requirement except for the sequences themselves. These characteristics make it particularly well suited for execution on microcomputers. Without slowing execution, the matching criterion can be that a specified fraction of contiguous bases must be identical. Even with gapped sequences, we have found large search windows to be surprisingly good for detecting poor homologies with nearly complete background suppression. A diagonal search pattern is used that reports the finds in a compact and logically ordered form. A simple and rapid plotting algorithm for unsophisticated printers is also reported

    Tourist spaces and tourism policy in Spain and Portugal

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    Advances in Cultura, Tourism and Hospitality Research;10, 235-249This study analyses the relationship between the development of the tourism policy of Spain and Portugal and their effects on regional imbalances. Despite the proximity of the two countries and their specialisation in tourism, there are few comparative studies on tourism of the two Iberian countries. The study focuses on the two major phases of tourism policy: the period of mass tourism and post-Fordist stage. In the conclusions we refer the debate on the existence of a model of development based on tourism to the Latin countries of Southern Europe and we note the export process of the Spanish low-cost tourism model to other countries.Financiado por el Gobierno de España, Programa Fundamental de Investigación, Proyecto de I+D (CSO2012-30840) "Geografías de la crisis: análisis de los territorios urbanos y turísticos de las Islas Baleares, Costa del Sol y principales destinos del Caribe y América Central"

    Critical perspectives on ‘consumer involvement’ in health research: epistemological dissonance and the know-do gap

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    Researchers in the area of health and social care (both in Australia and internationally) are encouraged to involve consumers throughout the research process, often on ethical, political and methodological grounds, or simply as ‘good practice’. This paper presents findings from a qualitative study in the UK of researchers’ experiences and views of consumer involvement in health research. Two main themes are presented in the paper. Firstly, we explore the ‘know-do gap’ which relates to the tensions between researchers’ perceptions of the potential benefits of, and their actual practices in relation to, consumer involvement. Secondly, we focus on one of the reasons for this ‘know-do gap’, namely epistemological dissonance. Findings are linked to issues around consumerism in research, lay/professional knowledges, the (re)production of professional and consumer identities and the maintenance of boundaries between consumers and researchers

    The complete nucleotide sequence of a beta-globin-like structure, beta h2, from the [Hbb] d mouse BALB/c.

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    We have determined the complete nucleotide sequence of beta h2, a pseudogene in the mouse beta-globin gene complex. The structure of beta h2 is analogous to that of a normal beta-globin gene, and its nucleotide sequence shares 72% homology with the coding regions of a reference mouse adult beta-globin gene. A frame shift occurs in the first coding region for which a compensatory splicing scheme can be devised. The reading frame is not otherwise disrupted. All of the recognized transcription, translation, and splicing signals in beta h2 are intact, with the exception of the " CCAAT box," which has been altered to GTAAC . We compared the predicted amino acid sequence of beta h2 with other beta-globin sequences. Evidence for a period of divergence without selection in the history of beta h2 was found in a set of codons that are usually highly conserved in productive beta-globin genes. An evolutionary tree constructed from nucleotide sequence suggests that beta h2 originated from the adult genes at least 60 million years ago. After some period as a productive gene, beta h2 was inactivated and has subsequently diverged without selection. Hybridization experiments demonstrated that beta h2 and the surrounding region occur without major alteration in other rodent species. The sequence ( AGCCA - 4n - GTGT ) occurs 5' of the CCAAT box in beta h2 and in many productive globin genes
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