Isabel Pavas - Academia.edu (original) (raw)
Papers by Isabel Pavas
PLOS One, 2011
Infection with Helicobacter pylori is the major cause for the development of peptic ulcer disease... more Infection with Helicobacter pylori is the major cause for the development of peptic ulcer disease (PUD). In children, with no other etiology for the disease, this rare event occurs shortly after infection. In these young patients, habits of smoking, diet, consumption of alcohol and non-steroid anti-inflammatory drugs and stress, in addition to the genetic susceptibility of the patient, represent a minor influence. Accordingly, the virulence of the implicated H. pylori strain should play a crucial role in the development of PUD. Corroborating this, our in vitro infection assays comparing a pool of five H. pylori strains isolated from children with PUD to a pool of five other pediatric clinical isolates associated with non-ulcer dyspepsia (NUD) showed the greater ability of PUD strains to induce a marked decrease in the viability of gastric cells and to cause severe damage in the cells cytoskeleton as well as an impairment in the production/secretion of mucins. To uncover virulence features, we compared the proteome of these two groups of H. pylori strains. Two-dimensional gel electrophoresis followed by massspectrometry allowed us to detect 27 differentially expressed proteins between them. In addition to the presence of genes encoding well established virulence factors, namely cagA, vacAs1, oipA ''on'' status, homB and jhp562 genes, the pediatric ulcerogenic strains shared a proteome profile characterized by changes in the abundance of: motility-associated proteins, accounting for higher motility; antioxidant proteins, which may confer increased resistance to inflammation; and enzymes involved in key steps in the metabolism of glucose, amino acids and urea, which may be advantageous to face fluctuations of nutrients. In conclusion, the enhanced virulence of the pediatric ulcerogenic H. pylori strains may result from a synergy between their natural ability to better adapt to the hostile human stomach and the expression of the established virulence factors.
Management Decision, 2008
Purpose -The purpose of this study is to analyse CSR practices implemented by Spanish companies a... more Purpose -The purpose of this study is to analyse CSR practices implemented by Spanish companies and the relationship between such practices and corporate financial performance. Design/methodology/approach -The empirical analysis carried out was performed in two phases or stages: analysis of the data obtained through content analysis; and analysis of the motivations behind CSR practices using a dependency model, multiple linear regression, enabling their effect on corporate performance to be explained. Several control variables were introduced to represent the size of the companies, expressed in terms of total assets, and the industry in which the firm operates. Findings -The paper underpins the fact that in Spain there has been a significant increase in practices favouring the reduction of environmental impact, as well as the creation of comfortable workplaces, especially promoting workers' rights. Several of these corporate practices associated with social responsibility in Spanish firms show a positive and significant impact on the rate of sales growth but there is a lack of impact on productivity or market value. Moreover, other responsible practices are not related to short-run improvements in companies' performance. Practical implications -The findings allow the authors to conclude that CSR practices in Spanish firms are geared towards social welfare, and that they are mainly associated with differentiation with regard to competitors and improving the company image, which lead to performance-linked economic advantages (such as sales increases). Originality/value -The paper has analysed corporate practices in a specific country separately (Spain) and has determined the relationship between CSR and firm performance.
Para nosotros, el emprendimiento social es la fusión entre una solución innovadora a un problema ... more Para nosotros, el emprendimiento social es la fusión entre una solución innovadora a un problema de desarrollo socio-económico y una estrategia sostenible con impacto medido. De la misma manera, la Fundación Ashoka define un emprendedor social como una persona con soluciones inovadoras a los problemas más graves en sus comunidades. Son ambiciosos y persistentes, atacando serios problemas de desarrollo social, cultural y económico. Un emprendedor social no espera a que el gobierno o el sector privado llegue a solucionar un problema social, sino buscan cambiarlo ellos mismos, liderando el cambio en sus comunidades.
PLOS One, 2011
Infection with Helicobacter pylori is the major cause for the development of peptic ulcer disease... more Infection with Helicobacter pylori is the major cause for the development of peptic ulcer disease (PUD). In children, with no other etiology for the disease, this rare event occurs shortly after infection. In these young patients, habits of smoking, diet, consumption of alcohol and non-steroid anti-inflammatory drugs and stress, in addition to the genetic susceptibility of the patient, represent a minor influence. Accordingly, the virulence of the implicated H. pylori strain should play a crucial role in the development of PUD. Corroborating this, our in vitro infection assays comparing a pool of five H. pylori strains isolated from children with PUD to a pool of five other pediatric clinical isolates associated with non-ulcer dyspepsia (NUD) showed the greater ability of PUD strains to induce a marked decrease in the viability of gastric cells and to cause severe damage in the cells cytoskeleton as well as an impairment in the production/secretion of mucins. To uncover virulence features, we compared the proteome of these two groups of H. pylori strains. Two-dimensional gel electrophoresis followed by massspectrometry allowed us to detect 27 differentially expressed proteins between them. In addition to the presence of genes encoding well established virulence factors, namely cagA, vacAs1, oipA ''on'' status, homB and jhp562 genes, the pediatric ulcerogenic strains shared a proteome profile characterized by changes in the abundance of: motility-associated proteins, accounting for higher motility; antioxidant proteins, which may confer increased resistance to inflammation; and enzymes involved in key steps in the metabolism of glucose, amino acids and urea, which may be advantageous to face fluctuations of nutrients. In conclusion, the enhanced virulence of the pediatric ulcerogenic H. pylori strains may result from a synergy between their natural ability to better adapt to the hostile human stomach and the expression of the established virulence factors.
Management Decision, 2008
Purpose -The purpose of this study is to analyse CSR practices implemented by Spanish companies a... more Purpose -The purpose of this study is to analyse CSR practices implemented by Spanish companies and the relationship between such practices and corporate financial performance. Design/methodology/approach -The empirical analysis carried out was performed in two phases or stages: analysis of the data obtained through content analysis; and analysis of the motivations behind CSR practices using a dependency model, multiple linear regression, enabling their effect on corporate performance to be explained. Several control variables were introduced to represent the size of the companies, expressed in terms of total assets, and the industry in which the firm operates. Findings -The paper underpins the fact that in Spain there has been a significant increase in practices favouring the reduction of environmental impact, as well as the creation of comfortable workplaces, especially promoting workers' rights. Several of these corporate practices associated with social responsibility in Spanish firms show a positive and significant impact on the rate of sales growth but there is a lack of impact on productivity or market value. Moreover, other responsible practices are not related to short-run improvements in companies' performance. Practical implications -The findings allow the authors to conclude that CSR practices in Spanish firms are geared towards social welfare, and that they are mainly associated with differentiation with regard to competitors and improving the company image, which lead to performance-linked economic advantages (such as sales increases). Originality/value -The paper has analysed corporate practices in a specific country separately (Spain) and has determined the relationship between CSR and firm performance.
Para nosotros, el emprendimiento social es la fusión entre una solución innovadora a un problema ... more Para nosotros, el emprendimiento social es la fusión entre una solución innovadora a un problema de desarrollo socio-económico y una estrategia sostenible con impacto medido. De la misma manera, la Fundación Ashoka define un emprendedor social como una persona con soluciones inovadoras a los problemas más graves en sus comunidades. Son ambiciosos y persistentes, atacando serios problemas de desarrollo social, cultural y económico. Un emprendedor social no espera a que el gobierno o el sector privado llegue a solucionar un problema social, sino buscan cambiarlo ellos mismos, liderando el cambio en sus comunidades.