948 resultados para Mature osteoblast


Relevância:

20.00% 20.00%

Publicador:

Resumo:

E-atmospherics have been often analyzed in terms of functional features, leaving its characteristics' link to social capital co-creation as a fertile research area. Prior research have demonstrated the capacity of e-atmospherics' at modifying shopping habits towards deeper engagement. Little is known on how processes and cues emerging from the social aspects of lifestyle influence purchasing behavior. The anatomy of social dimension and ICT is the focus of this research, where attention is devoted to unpack the meanings and type of online mundane social capital creation. Taking a cross-product/services approach to better investigate social construction impact, our approach also involves both an emerging and a mature market where exploratory content analysis of landing page are done on Turkish and French web sites, respectively. We contend that by comprehending social capital, daily micro practices, habits and routine, a better and deeper understanding on e-atmospherics incumbent and potential effects on its multi-national e-customer will be acquired.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The density of diffuse, primitive, classic and compact beta/A4 deposits was estimated in the cortex and hippocampus in Alzheimer's disease (AD) cases with and without pronounced congophilic angiopathy (CA). The total density of beta/A4 deposits in a given brain region was similar in cases with and without CA. Significantly fewer diffuse deposits and more primitive/classic deposits were found in the cases with CA. The densities of the primitive, classic and compact deposits were positively correlated in the cases without CA. However, no correlations were observed between the density of the mature subtypes and the diffuse deposits in these cases. In the cases with CA, the density of the primitive deposits was positively correlated with the diffuse but not with the classic deposits. The data suggest that the mature beta/A4 deposits are derived from the diffuse deposits and that the presence of pronounced CA enhances their formation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The density of diffuse, primitive, classic and compact beta/A4 deposits was estimated in the cortex and hippocampus in Alzheimer's disease (AD) cases with pronounced congophilic angiopathy (CA). The total density of beta/A4 deposits in a brain region was similar in cases with and without CA. Significantly fewer diffuse deposits and more primitive/classic deposits were found in the cases with CA. The density of the primitive, classic and compact deposits were positively correlated in the cases without CA. However, no correlations were observed between the density of the mature subtypes and the diffuse deposits in these cases. In cases with CA, the density of the primitive deposits was positively correlated with the diffuse deposits but not with the classic deposits. The data suggest that the mature beta/A4 deposits are derived from the diffuse deposits and that the presence of pronounced CA enhances their formation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis is concerned with the management of product innovation inside the medium size, mature, manufacturing company. An academic perspective of innovation is integrated with an account of direct participation acquired over a two year period. The emergent synthesis provides fresh insight into some of the problems associated with producing and sustaining innovation. Product innovation is a very complex activity, and it presents particular difficulties for mature industry. However, the ability to innovate is fundamental to a company's continued survival. Three aspects of product innovation are examined in detail. Firstly, is the requirement to separate innovation activity from the on-going business interests; dependency between the degree of separation and novelty is supported. Secondly, a simple sequential model of the innovation process is tested and shown to be of considerable practical value. Thirdly a relationship is established between the age of the recipient market and the type of innovation to be found in that market All three aspects are found to have important implications for management in their pursuit of innovation. Management deficiencies which inhibited the successful resolution of innovation-linked problems are described and solutions which stress the need for commitment and coherency are proposed. The long existing management structure in the mature company which mitigates against successful and continuing innovation are examined in detail and a strategy is evolved which uses the intrinsic strengths of the mature company to promote innovation of a kind compatible with success in the market. A set of guidelines of practical value is presented for those managers wishing to pursue, and sustain, product innovation in the medium size mature company.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tissue transglutaminase (TG2) has been identified as an important extracellular crosslinking enzyme involved in matrix turnover and in bone differentiation. Here we report a novel cell adhesion/survival mechanism in human osteoblasts (HOB) which requires association of FN bound TG2 with the cell surface heparan sulphates in a transamidase independent manner. This novel pathway not only enhances cell adhesion on FN but also mediates cell adhesion and survival in the presence of integrin competing RGD peptides. We investigate the involvement of cell surface receptors and their intracellular signalling molecules to further explore the pathway mediated by this novel TG-FN heterocomplex. We demonstrate by siRNA silencing the crucial importance of the cell surface heparan sulphate proteoglycans syndecan-2 and syndecan-4 in regulating the compensatory effect of TG-FN on osteoblast cell adhesion and actin cytoskeletal formation in the presence of RGD peptides. By use of immunoprecipitation and inhibitory peptides we show that syndecan-4 interacts with TG2 and demonstrate that syndecan-2 and the a5ß1 integrins, but not a4ß1 function as downstream modulators in this pathway. Using function blocking antibodies, we show activation of a5ß1 occurs by an inside out signalling mechanism involving activation and binding of protein kinase PKCa and phosphorylation of focal adhesion kinase (FAK) at Tyr861 and activation of ERK1/2.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Leukemia inhibitory factor (LIF) and its receptor (LIFR) are "twins" of Oncostatin M (OSM) and OSMR, respectively, likely having arisen through gene duplications. We compared their effects in a bone nodule-forming model of in vitro osteogenesis, rat calvaria (RC) cell cultures. Using a dominant-negative LIF mutant (hLIF-05), we showed that in RC cell cultures mouse OSM (mOSM) activates exclusively glycoprotein 130 (gp130)/OSMR. In treatments starting at early nodule formation stage, LIF, mOSM, IL-11, and IL-6 + sIL-6R inhibit bone nodule formation, that is, osteoprogenitor differentiation. Treatment with mOSM, and no other cytokine of the family, in early cultures (day 1-3 or 1-4) increases bone colony numbers. hLIF-05 also dose dependently stimulates bone nodule formation, confirming the inhibitory action of gp130/LIFR on osteogenesis. In pulse treatments at successive stages of bone nodule formation and maturation, LIF blocks osteocalcin (OCN) expression by differentiated osteoblasts, but has no effect on bonesialoprotein (BSP) expression. Mouse OSM inhibits OCN and BSP expression in preconfluent cultures with no or progressively reduced effects at later stages, reflecting the disruption of early nodules, possibly due to the strong apoptotic action of mOSM in RC cell cultures. In summary, LIFR and OSMR display differential effects on differentiation and phenotypic expression of osteogenic cells, most likely through different signal transduction pathways. In particular, gp130/OSMR is the only receptor complex of the family to stimulate osteoprogenitor differentiation in the RC cell culture model. © 2005 Wiley-Liss, Inc.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The forces of globalisation now impacting on local economies pose threats to the existing paradigm of competences and routines, yet simultaneously offer opportunities to integrate new knowledge and learning. This is particularly pertinent with respect to Europe’s ‘mature regions’, which are undergoing a major economic restructuring by trying to shift from traditional manufacturing activities to hybrid activities that comprise a combination of manufacturing and a higher component of intangible inputs and related knowledge service activities. The objective of the article is to discuss the concept of ‘place leadership’ by looking at how the embedded skills, knowledge and cumulated learning of a place can be used by its institutional infrastructure to identify sustainable growth trajectories. In other words, its aim is to explore how the economic, social, institutional and cultural aspects of places shape the opportunities for upgrading and renovation drawing upon their historical specialisation. The conceptual contribution of the article draws on two case studies, in the West Midlands, UK and in Prato, Tuscany, where we study the processes of decision-making, forms of leadership and ultimately the nature of local leadership.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tissue transglutaminase (tTG) is a calcium-dependent and guanosine 5'-triphosphate (GTP) binding enzyme, which catalyzes the post-translational modification of proteins by forming intermolecular ε(ϒ-glutamyl)lysine cross-links. In this study, human osteoblasts (HOBs) isolated from femoral head trabecular bone and two osteosarcoma cell lines (HOS and MG-63) were studied for their expression and localization of tTG. Quantitative evaluation of transglutaminase (TG) activity determined using the [1,414C]-putrescine incorporation assay showed that the enzyme was active in all cell types. However, there was a significantly higher activity in the cell homogenates of MG-63 cells as compared with HOB and HOS cells (p <0.001). There was no significant difference between the activity of the enzyme in HOB and HOS cells. All three cell types also have a small amount of active TG on their surface as determined by the incorporation of biotinylated cadaverine into fibronectin. Cell surface-related tTG was further shown by preincubation of cells with tTG antibody, which led to inhibition of cell attachment. Western blot analysis clearly indicated that the active TG was tTG and immunocytochemistry showed it be situated in the cytosol of the cells. In situ extracellular enzyme activity also was shown by the cell-mediated incorporation of fluorescein cadaverine into extracellular matrix (ECM) proteins. These results clearly showed that MG-63 cells have high extracellular activity, which colocalized with the ECM protein fibronectin and could be inhibited by the competitive primary amine substrate putrescine. The contribution of tTG to cell surface/matrix interactions and to the stabilization of the ECM of osteoblast cells therefore could by an important factor in the cascade of events leading to bone differentiation and mineralization.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The mature market, defined as age 55 and up and consisting of approximately 64 million Americans, is expected to increase. Studies show that this group travels more frequently, travels greater distances, and stays longer. The authors seek to determine if underlying dimensions exist for the mature individual with regard to the selection criteria for lodging when traveling for pleasure, and to determine if differences exist between various demographic subsegments of this market with regard to these underlying dimensions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article is a reflection of a study conducted with active mature consumers who enjoy dining out, traveling, and patronizing the service industry in general. The goal was to discover their restaurant service expectations in order to provide restaurateurs, hoteliers, educators, and students of hospitality management programs information about this important customer segment so that future plans for improving service would include considerations of their service needs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

[EN] Marine turtles commonly carry diverse forms of epizoa on their shells. The occurrence of a particular species may ultimately help to clarify certain questions about sea turtle natural life history. This paper gives a detailed and comparative list of epizoic species found on two populations of macaronesian loggerheads: pelagic and juveniles living around the Canary Islands and mature females nesting in Boavista Island, Cabo Verde. For the epizoic flora, the most important genera founded is Polysiphonia (Rhodophiceae); P. carettia for the pelagics and Polysiphonia sp. for the nesting animals.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the first part of this thesis, the oncogenic potential of TCL1A family genes was comparatively evaluated by using gamma-retroviral vectors to introduce human TCL1A, MTCP1, and TML1 into hematopoietic stem cells/hematopoietic progenitor cells (HSC/HPC) of wild type mice that were transplanted into wild type recipients. TCL1A and MTCP1 recipient mice predominantly developed B-cell malignancies after a median survival of 388 days and 394 days, respectively. The presented data indicates that TCL1A and MTCP1 are oncogenes with comparable oncogenic potential and shows for the first time that MTCP1 is not only a T-cell oncogene, but is able to transform B cells as well. The third family member TML1 induced the development of immature T-cell malignancies in only a few mice. This study provides first evidence for its oncogenic function. Additionally, the transforming potential of compartment-targeted TCL1A variants was evaluated by retroviral expression of a membrane localizing myristoylated (myr-TCL1A) and a nuclear localizing (nls-TCL1A) variant. Recipients of HSC/HPC transduced with myr-TCL1A and nls-TCL1A predominantly developed B-cell malignancies after a median survival of 360 days and 349 days, respectively. There was a significantly shorter latency period for nls-TCL1A compared to the previously described generic TCL1A. Gene expression analysis revealed higher similarities between expression profiles of tumors induced by TCL1A and nls-TCL1A. Together these data implicate that TCL1A’s predominant oncogenic function might rely on its nuclear presence. The second part of this thesis aims to understand if and how TCR stimulation affects the transforming potential of TCL1A. Mature OT-1 T cells carrying monoclonal TCR’s that specifically recognize ovalbumin (OVA) were retrovirally transduced with TCL1A and repeatedly stimulated in vivo with OVA-peptides. TCR stimulated recipient mice of TCL1A transduced T cells showed a significantly accelerated leukemic outgrowth and a reduced median survival of 305 days, when compared to unstimulated recipients (417 days). These data strongly implicate a pro-leukemogenic cooperation of TCL1A and TCR signals that might be actionable in upcoming interventional designs.