68 research outputs found

    Paced Auditory Serial Addition Task : an experimental investigation : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University

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    This study investigated the effects of seven independent variables upon a Paced Auditory Serial Addition Task (PASAT; Gronwall & Sampson, 1974). The main effects found were that arithmetic ability and a short-term memory measure were related to performance on this task. Interactive effects were found for measures of anxiety, sex and the strategy used in performing the PASAT. Theories considered included those of Broadbent (1977), Neisser (1976), Kerr (1973), Kahneman (1973) and Broadbent (1971) with emphasis on the latter two. The findings are most easily interpreted in terms of Kahneman's (1973) theory. Broadbent's (1971) model could not account for the effects of environmental and task conditions upon information-processing capacity. Further research is needed to examine the effects of individual abilities and biases in selective attention. Also it is suggested that perception and the allocation of effort policy (Kahneman, 1973) be studied further from Broadbent's (1977) perspective of global and local analysis of information. Clinical implications for the interpretation of the PASAT are discussed. It is suggested that this test could be used more widely as a measure of selective attention. More specifically it is suggested that the administration instructions could be simplified where necessary; and error scores considered together with rate of performance. These measures give an indication of performance effectiveness

    The effectiveness of daclatasvir based therapy in European patients with chronic hepatitis C and advanced liver disease

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    Daclatasvir; Eficàcia; Hepatitis CDaclatasvir; Eficacia; Hepatitis CDaclatasvir; Effectiveness; Hepatitis CBackground There is limited evidence for the effectiveness of daclatasvir in patients whose hepatitis C threatens their life expectancy. The Named Patient Program in Europe included patients with advanced chronic hepatitis C, a life expectancy of less than 12 months and no other treatment options. Methods A retrospective multi-country cohort of patients with chronic hepatitis C who received daclatasvir as part of the Named Patient Program in Austria, Denmark, Spain, Sweden, Switzerland and the United Kingdom. Treatment response was defined as a sustained virologic response (unquantifiable hepatitis C RNA) at 12 weeks post treatment. We summarised the characteristics of the patients in this cohort and estimated the rate of sustained virologic response for patients receiving daclatasvir and sofosbuvir with or without ribavirin using hierarchical Bayesian modelling. Results The 249 patients included had a median age of 56 years; most were male (78%), hepatitis C genotype 1 (75%), treatment experienced (65%) and with decompensated cirrhosis (59%). Many had had a liver transplant before receiving daclatasvir (40%). Of the 249 patients, 242 patients received daclatasvir and sofosbuvir and either reached 12 weeks post treatment or died during (n = 9) or after treatment (n = 4) or were lost to follow up during treatment (n = 1). The estimated rate of sustained virologic response at 12 weeks post treatment was 87% (95% credible interval 75 to 94%) for previously treated genotype 1 patients with decompensated cirrhosis. Conclusions Daclatasvir with sofosbuvir is an effective treatment in clinical practice for hepatitis C genotype 1 patients with decompensated cirrhosis.This work was supported by BMS

    Patterning of educational attainment across inflammatory markers : Findings from a multi-cohort study

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    Background: Evidence suggests that the inflammatory reaction, an adaptive response triggered by a variety of harmful stimuli and conditions involved in the risk and development of many chronic diseases, is a potential pathway through which the socioeconomic environment is biologically embedded. Difficulty in interpreting the role of the inflammatory system in the embodiment dynamic arises because of heterogeneity across studies that use a limited but varied number of inflammatory markers. There is no consensus in the literature as to which inflammatory markers beyond the C-reactive protein and to a lesser extent interleukin 6 are related to the social environment. Accordingly, we aimed to investigate the association between educational attainment, and several markers of inflammation - C-reactive protein, fibrinogen, interleukin 6, interleukin 1 beta and tumor necrosis factor alpha- in 6 European cohort studies. Methods: Up to 17,470 participants from six European cohort studies with data on educational attainment, health behaviors and lifestyle factors, and at least two different inflammatory markers. Four sub-datasets were drawn with varying numbers of participants to allow pairwise comparison of the social patterning of C-reactive protein and any other inflammatory markers. To evaluate within each sub-dataset the importance of the context and cohort specificities, linear regression-based analyses were performed separately for each cohort and combined in a random effect meta-analysis to determine the relationship between educational attainment and inflammation. Results: We found that the magnitude of the relationship between educational attainment and five inflammatory biomarkers (C-reactive protein, fibrinogen, interleukin 6 and 1 beta and tumor necrosis factor alpha) was variable. By far the most socially patterned biomarker was C-reactive protein, followed by fibrinogen and to lesser extent interleukin 6, where a low educational attainment was associated with higher inflammation even after adjusting for health behaviours and body mass index. No association was found with interleukin 1 beta and tumor necrosis factor alpha. Conclusions: Our study suggests different educational patterning of inflammatory biomarkers. Further large-scale research is needed to explore social differences in the inflammatory cascade in greater detail and the extent to which these differences contribute to social inequalities in health.Peer reviewe

    The effectiveness of daclatasvir based therapy in European patients with chronic hepatitis C and advanced liver disease

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    [Background] There is limited evidence for the effectiveness of daclatasvir in patients whose hepatitis C threatens their life expectancy. The Named Patient Program in Europe included patients with advanced chronic hepatitis C, a life expectancy of less than 12 months and no other treatment options.Methods`] A retrospective multi-country cohort of patients with chronic hepatitis C who received daclatasvir as part of the Named Patient Program in Austria, Denmark, Spain, Sweden, Switzerland and the United Kingdom. Treatment response was defined as a sustained virologic response (unquantifiable hepatitis C RNA) at 12 weeks post treatment. We summarised the characteristics of the patients in this cohort and estimated the rate of sustained virologic response for patients receiving daclatasvir and sofosbuvir with or without ribavirin using hierarchical Bayesian modelling.[Results] The 249 patients included had a median age of 56 years; most were male (78%), hepatitis C genotype 1 (75%), treatment experienced (65%) and with decompensated cirrhosis (59%). Many had had a liver transplant before receiving daclatasvir (40%). Of the 249 patients, 242 patients received daclatasvir and sofosbuvir and either reached 12 weeks post treatment or died during (n = 9) or after treatment (n = 4) or were lost to follow up during treatment (n = 1). The estimated rate of sustained virologic response at 12 weeks post treatment was 87% (95% credible interval 75 to 94%) for previously treated genotype 1 patients with decompensated cirrhosis.[Conclusions] Daclatasvir with sofosbuvir is an effective treatment in clinical practice for hepatitis C genotype 1 patients with decompensated cirrhosis.This work was supported by BMS.Peer reviewe

    Patterning of educational attainment across inflammatory markers: Findings from a multi-cohort study

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    Background: Evidence suggests that the inflammatory reaction, an adaptive response triggered by a variety of harmful stimuli and conditions involved in the risk and development of many chronic diseases, is a potential pathway through which the socioeconomic environment is biologically embedded. Difficulty in interpreting the role of the inflammatory system in the embodiment dynamic arises because of heterogeneity across studies that use a limited but varied number of inflammatory markers. There is no consensus in the literature as to which inflammatory markers beyond the C-reactive protein and to a lesser extent interleukin 6 are related to the social environment. Accordingly, we aimed to investigate the association between educational attainment, and several markers of inflammation - C-reactive protein, fibrinogen, interleukin 6, interleukin 1 beta and tumor necrosis factor alpha- in 6 European cohort studies.Methods: Up to 17,470 participants from six European cohort studies with data on educational attainment, health behaviors and lifestyle factors, and at least two different inflammatory markers. Four sub-datasets were drawn with varying numbers of participants to allow pairwise comparison of the social patterning of C-reactive protein and any other inflammatory markers. To evaluate within each sub-dataset the importance of the context and cohort specificities, linear regression-based analyses were performed separately for each cohort and combined in a random effect meta-analysis to determine the relationship between educational attainment and inflammation.Results: We found that the magnitude of the relationship between educational attainment and five inflammatory biomarkers (C-reactive protein, fibrinogen, interleukin 6 and 1 beta and tumor necrosis factor alpha) was variable. By far the most socially patterned biomarker was C-reactive protein, followed by fibrinogen and to lesser extent interleukin 6, where a low educational attainment was associated with higher inflammation even after adjusting for health behaviours and body mass index. No association was found with interleukin 1 beta and tumor necrosis factor alpha.Conclusions: Our study suggests different educational patterning of inflammatory biomarkers. Further large-scale research is needed to explore social differences in the inflammatory cascade in greater detail and the extent to which these differences contribute to social inequalities in health.</div

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
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