877 resultados para Formative constructs
Resumo:
The high Km glucose transporter GLUT2 is a membrane protein expressed in tissues involved in maintaining glucose homeostasis, and in cells where glucose-sensing is necessary. In many experimental models of diabetes, GLUT2 gene expression is decreased in pancreatic beta-cells, which could lead to a loss of glucose-induced insulin secretion. In order to identify factors involved in pancreatic beta-cell specific expression of GLUT2, we have recently cloned the murine GLUT2 promoter and identified cis-elements within the 338-bp of the proximal promoter capable of binding islet-specific trans-acting factors. Furthermore, in transient transfection studies, this 338-bp fragment could efficiently drive the expression of the chloramphenicol acetyl transferase (CAT) gene in cell lines derived from the endocrine pancreas, but displayed no promoter activity in non-pancreatic cells. In this report, we tested the cell-specific expression of a CAT reporter gene driven by a short (338 bp) and a larger (1311 bp) fragment of the GLUT2 promoter in transgenic mice. We generated ten transgenic lines that integrated one of the constructs. CAT mRNA expression in transgenic tissues was assessed using the RNAse protection assay and the quantitative reverse transcribed polymerase chain reaction (RT-PCR). Overall CAT mRNA expression for both constructs was low compared to endogenous GLUT2 mRNA levels but the reporter transcript could be detected in all animals in the pancreatic islets and the liver, and in a few transgenic lines in the kidney and the small intestine. The CAT protein was also present in Langerhans islets and in the liver for both constructs by immunocytochemistry. These findings suggest that the proximal 338 bp of the murine GLUT2 promoter contain cis-elements required for the islet-specific expression of GLUT2.
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The cytokine macrophage migration inhibitory factor plays a central role in inflammation, cell proliferation and tumorigenesis. Moreover, macrophage migration inhibitory factor levels correlate with tumor aggressiveness and metastatic potential. Histone deacetylase inhibitors are potent antitumor agents recently introduced in the clinic. Therefore, we hypothesized that macrophage migration inhibitory factor would represent a target of histone deacetylase inhibitors. Confirming our hypothesis, we report that histone deacetylase inhibitors of various chemical classes strongly inhibited macrophage migration inhibitory factor expression in a broad range of cell lines, in primary cells and in vivo. Nuclear run on, transient transfection with macrophage migration inhibitory factor promoter reporter constructs and transduction with macrophage migration inhibitory factor expressing adenovirus demonstrated that trichostatin A (a prototypical histone deacetylase inhibitor) inhibited endogenous, but not episomal, MIF gene transcription. Interestingly, trichostatin A induced a local and specific deacetylation of macrophage migration inhibitory factor promoter-associated H3 and H4 histones which did not affect chromatin accessibility but was associated with an impaired recruitment of RNA polymerase II and Sp1 and CREB transcription factors required for basal MIF gene transcription. Altogether, this study describes a new molecular mechanism by which histone deacetylase inhibitors inhibit MIF gene expression, and suggests that macrophage migration inhibitory factor inhibition by histone deacetylase inhibitors may contribute to the antitumorigenic effects of histone deacetylase inhibitors.
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A successful bone tissue engineering strategy entails producing bone-scaffold constructs with adequate mechanical properties. Apart from the mechanical properties of the scaffold itself, the forming bone inside the scaffold also adds to the strength of the construct. In this study, we investigated the role of in vivo cyclic loading on mechanical properties of a bone scaffold. We implanted PLA/β-TCP scaffolds in the distal femur of six rats, applied external cyclic loading on the right leg, and kept the left leg as a control. We monitored bone formation at 7 time points over 35 weeks using time-lapsed micro-computed tomography (CT) imaging. The images were then used to construct micro-finite element models of bone-scaffold constructs, with which we estimated the stiffness for each sample at all time points. We found that loading increased the stiffness by 60% at 35 weeks. The increase of stiffness was correlated to an increase in bone volume fraction of 18% in the loaded scaffold compared to control scaffold. These changes in volume fraction and related stiffness in the bone scaffold are regulated by two independent processes, bone formation and bone resorption. Using time-lapsed micro-CT imaging and a newly-developed longitudinal image registration technique, we observed that mechanical stimulation increases the bone formation rate during 4-10 weeks, and decreases the bone resorption rate during 9-18 weeks post-operatively. For the first time, we report that in vivo cyclic loading increases mechanical properties of the scaffold by increasing the bone formation rate and decreasing the bone resorption rate.
Resumo:
This research aimed to identify political-ethical skills developed in a training process compatible with the expected profile set by the National Curriculum Guidelines for the Undergraduate Nursing Degree. A case study was conducted with units represented by 32 former students from a particular religious teaching institution who already were in the job market. The content of the interviews was analyzed using the thematic analysis technique, which resulted in the following categories: "Political-ethical skills in the formative process" and "Political-ethical skills as a product of the educational process." From the former students’ perspective, these categories reinforced the social role of the nurse and the need for students to be reflective, understanding and participative in the transformation of society.
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In this paper we study the relevance of multiple kernel learning (MKL) for the automatic selection of time series inputs. Recently, MKL has gained great attention in the machine learning community due to its flexibility in modelling complex patterns and performing feature selection. In general, MKL constructs the kernel as a weighted linear combination of basis kernels, exploiting different sources of information. An efficient algorithm wrapping a Support Vector Regression model for optimizing the MKL weights, named SimpleMKL, is used for the analysis. In this sense, MKL performs feature selection by discarding inputs/kernels with low or null weights. The approach proposed is tested with simulated linear and nonlinear time series (AutoRegressive, Henon and Lorenz series).
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Objective: To identify the frequency and intensity of moral distress experienced by nurses, technicians and nursing assistants who worked in hospitals in the South of Rio Grande do Sul State. Method: A survey research was conducted with 334 nursing workers from three institutions, through a questionnaire of moral distress. Constructs were validated through factorial analysis and Cronbach’s alpha: lack of competence of the working team, disrespect to the patient’s autonomy, insufficient working conditions and therapeutic obstinacy. Results: With descriptive statistics and analysis of variance, it was found that nurses and nursing assistants have higher perception of moral distress when compared to nursing technicians. Organizational questions and ways of communication influence lower perception of moral distress.Conclusion: Implementation of actions to favor coping, decision making and autonomy exercise from those workers.
Resumo:
OBJECTIVE: The effect of minor orthopaedic day surgery (MiODS) on patient's mood. METHODS: A prospective population-based cohort study of 148 consecutive patients with age above 18 and less than 65, an American Society of Anaesthesiology (ASA) score of 1, and the requirement of general anaesthesia (GA) were included. The Medical Outcomes Study - Short Form 36 (SF-36), Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI) were used pre- and post-operatively. RESULTS: The mean physical component score of SF-36 before surgery was 45.3 (SD=+/-10.1) and 8 weeks following surgery was 44.9 (SD=+/-11.04) [n=148, p=0.51, 95% CI=(-1.03 to 1.52)]. For the measurement of the changes in mood using BDI, BAI and SF-36, latent construct modelling was employed to increase validity. The covariance between mood pre- and post-operatively (cov=69.44) corresponded to a correlation coefficient, r=0.88 indicating that patients suffering a greater number of mood symptoms before surgery continue to have a greater number of symptoms following surgery. When the latent mood constructs were permitted to have different means the model fitted well with chi(2) (df=1)=0.86 for which p=0.77, thus the null hypothesis that MiODS has no effect on patient mood was rejected. CONCLUSIONS: MiODS affects patient mood which deteriorates at 8 weeks post-operatively regardless of the pre-operative patient mood state. More importantly patients suffering a greater number of mood symptoms before MiODS continue to have a greater number of symptoms following surgery.
Development and validation of an instrument for evaluating the ludicity of games in health education
Resumo:
Abstract OBJECTIVE Developing and validating an instrument to evaluate the playfulness of games in health education contexts. METHODOLOGY A methodological, exploratory and descriptive research, developed in two stages: 1. Application of an open questionnaire to 50 graduate students, with content analysis of the answers and calculation of Kappa coefficient for defining items; 2. Procedures for construction of scales, with content validation by judges and analysis of the consensus estimate byContent Validity Index(CVI). RESULTS 53 items regarding the restless character of the games in the dimensions of playfulness, the formative components of learning and the profiles of the players. CONCLUSION Ludicity can be assessed by validated items related to the degree of involvement, immersion and reinvention of the subjects in the game along with the dynamics and playability of the game.
Resumo:
El projecte realitzat se situa en el marc de la història contemporània, i s’ha centrat en primer lloc, en l’anàlisi, des d’una perspectiva comparativa, del desenvolupament dels discursos de gènere a Catalunya durant la Dictadura Franquista i a la Irlanda postcolonial. Mitjançant l’anàlisi del discurs, s’han estudiat els models de feminitat imposats pel Franquisme i les seves bases ideològiques com són el valors catòlics i l’antindividualisme. En el cas irlandès, s’ha analitzat com, a través de determinades institucions gestionades per l’Església Catòlica, es controlaven aquelles dones que es desviaven del model de gènere que propugnava l’Estat Irlandès, molt similar al proposat pel Franquisme i també basat en els catolicisme. De la mateix manera, s’ha estudiat com el feminisme Català i irlandès dels anys 1970 i 1980 van contrarestar aquests models de gènere imposats, a través de l’anàlisi d’un conjunt d’expressions culturals produïdes per ambdós moviments feministes. La perspectiva comparativa del projecte ha permès: El coneixement dels mecanismes culturals de repressió de les dones així com la seva institucionalització. Revelant els paral•lelismes pel que fa a les polítiques de gènere entre els dos casos estudiats malgrat diferències significatives entre els dos contextos (Catalunya es troba sota una dictadura, Irlanda és un Estat democràtic). La importància de l’agència de les dones i les seves diverses estratègies de resistència, especialment a través d’expressions culturals més efímeres o considerades frívoles que, malgrat el poc reconeixement que han obtingut, són molt eficaces en la deconstrucció de discursos de gènere repressius envers les dones. Ha posat de manifest, també, la importància de l’experiència i les pràctiques personals i íntimes com a pràctiques de resistència. Així mateix, ha visibilitzat les dinàmiques pròpies de moviments feministes.
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The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES), a 19-item instrument developed to assess readiness to change alcohol use among individuals presenting for specialized alcohol treatment, has been used in various populations and settings. Its factor structure and concurrent validity has been described for specialized alcohol treatment settings and primary care. The purpose of this study was to determine the factor structure and concurrent validity of the SOCRATES among medical inpatients with unhealthy alcohol use not seeking help for specialized alcohol treatment. The subjects were 337 medical inpatients with unhealthy alcohol use, identified during their hospital stay. Most of them had alcohol dependence (76%). We performed an Alpha Factor Analysis (AFA) and Principal Component Analysis (PCA) of the 19 SOCRATES items, and forced 3 factors and 2 components, in order to replicate findings from Miller and Tonigan (Miller, W. R., & Tonigan, J. S., (1996). Assessing drinkers' motivations for change: The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES). Psychology of Addictive Behavior, 10, 81-89.) and Maisto et al. (Maisto, S. A., Conigliaro, J., McNeil, M., Kraemer, K., O'Connor, M., & Kelley, M. E., (1999). Factor structure of the SOCRATES in a sample of primary care patients. Addictive Behavior, 24(6), 879-892.). Our analysis supported the view that the 2 component solution proposed by Maisto et al. (Maisto, S.A., Conigliaro, J., McNeil, M., Kraemer, K., O'Connor, M., & Kelley, M.E., (1999). Factor structure of the SOCRATES in a sample of primary care patients. Addictive Behavior, 24(6), 879-892.) is more appropriate for our data than the 3 factor solution proposed by Miller and Tonigan (Miller, W. R., & Tonigan, J. S., (1996). Assessing drinkers' motivations for change: The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES). Psychology of Addictive Behavior, 10, 81-89.). The first component measured Perception of Problems and was more strongly correlated with severity of alcohol-related consequences, presence of alcohol dependence, and alcohol consumption levels (average number of drinks per day and total number of binge drinking days over the past 30 days) compared to the second component measuring Taking Action. Our findings support the view that the SOCRATES is comprised of two important readiness constructs in general medical patients identified by screening.
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IGF2 is an autocrine ligand for the beta cell IGF1R receptor and GLP-1 increases the activity of this autocrine loop by enhancing IGF1R expression, a mechanism that mediates the trophic effects of GLP-1 on beta cell mass and function. Here, we investigated the regulation of IGF2 biosynthesis and secretion. We showed that glutamine rapidly and strongly induced IGF2 mRNA translation using reporter constructs transduced in MIN6 cells and primary islet cells. This was followed by rapid secretion of IGF2 via the regulated pathway, as revealed by the presence of mature IGF2 in insulin granule fractions and by inhibition of secretion by nimodipine and diazoxide. When maximally stimulated by glutamine, the amount of secreted IGF2 rapidly exceeded its initial intracellular pool and tolbutamide, and high K(+) increased IGF2 secretion only marginally. This indicates that the intracellular pool of IGF2 is small and that sustained secretion requires de novo synthesis. The stimulatory effect of glutamine necessitates its metabolism but not mTOR activation. Finally, exposure of insulinomas or beta cells to glutamine induced Akt phosphorylation, an effect that was dependent on IGF2 secretion, and reduced cytokine-induced apoptosis. Thus, glutamine controls the activity of the beta cell IGF2/IGF1R autocrine loop by increasing the biosynthesis and secretion of IGF2. This autocrine loop can thus integrate changes in feeding and metabolic state to adapt beta cell mass and function.
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One plausible mechanism through which financial market shocks may propagate across countriesis through the impact that past gains and losses may have on investors risk aversion and behavior. This paper presents a stylized model illustrating how heterogeneous changes in investors risk aversion affect portfolio allocation decisions and stock prices. Our empirical findings suggest that when funds returns are below average, they adjust their holdings toward the average (or benchmark) portfolio. In so doing, funds tend to sell the assets of countries in which they were overweight , increasing their exposure to countries in which they were underweight. Based on this insight, the paper constructs an index of financial interdependence which reflects the extent to which countries share overexposed funds. The index helps in explain the pattern of stock market comovement across countries. Moreover, a comparison of this interdependence measure to indices of trade or commercial bank linkages indicates that our index can improve predictions about which countries are more likely to be affected by contagion from crisis centers.
Resumo:
Bacterial cell-wall-associated fibronectin binding proteins A and B (FnBPA and FnBPB) form bonds with host fibronectin. This binding reaction is often the initial step in prosthetic device infections. Atomic force microscopy was used to evaluate binding interactions between a fibronectin-coated probe and laboratory-derived Staphylococcus aureus that are (i) defective in both FnBPA and FnBPB (fnbA fnbB double mutant, DU5883), (ii) capable of expressing only FnBPA (fnbA fnbB double mutant complemented with pFNBA4), or (iii) capable of expressing only FnBPB (fnbA fnbB double mutant complemented with pFNBB4). These experiments were repeated using Lactococcus lactis constructs expressing fnbA and fnbB genes from S. aureus. A distinct force signature was observed for those bacteria that expressed FnBPA or FnBPB. Analysis of this force signature with the biomechanical wormlike chain model suggests that parallel bonds form between fibronectin and FnBPs on a bacterium. The strength and covalence of bonds were evaluated via nonlinear regression of force profiles. Binding events were more frequent (p < 0.01) for S. aureus expressing FnBPA or FnBPB than for the S. aureus double mutant. The binding force, frequency, and profile were similar between the FnBPA and FnBPB expressing strains of S. aureus. The absence of both FnBPs from the surface of S. aureus removed its ability to form a detectable bond with fibronectin. By contrast, ectopic expression of FnBPA or FnBPB on the surface of L. lactis conferred fibronectin binding characteristics similar to those of S. aureus. These measurements demonstrate that fibronectin-binding adhesins FnBPA and FnBPB are necessary and sufficient for the binding of S. aureus to prosthetic devices that are coated with host fibronectin.
Resumo:
Genetic experiments established that p63 is crucial for the development and maintenance of pluristratified epithelia. In the RNA interference (RNAi) screening for targets of p63 in keratinocytes, we identified the transcription factor, High Mobility Group (HMG) box protein 1 (HBP1). HBP1 is an HMG-containing repressor transiently induced during differentiation of several cell lineages. We investigated the relationship between the two factors: using RNAi, overexpression, chromatin immunoprecipitations and transient transfections with reporter constructs, we established that HBP1 is directly repressed by p63. This was further confirmed in vivo by evaluating expression in p63 knockout mice and in transgenics expressing p63 in basal keratinocytes. Consistent with these findings, expression of HBP1 increases upon differentiation of primary keratinocytes and HaCaT cells in culture, and it is higher in the upper layers of human skin. Inactivation of HBP1 by RNAi prevents differentiation of keratinocytes and stratification of organotypic skin cultures. Finally, we analyzed the keratinocyte transcriptomes after HBP1 RNAi; in addition to repression of growth-promoting genes, unexpected activation of differentiation genes was uncovered, coexisting with repression of other genes involved in epithelial cornification. Our data indicate that suppression of HBP1 is part of the growth-promoting strategy of p63 in the lower layers of epidermis and that HBP1 temporally coordinates expression of genes involved in stratification, leading to the formation of the skin barrier.