Emerging Understanding (emerging + understanding)

Distribution by Scientific Domains

Selected Abstracts

Fat as a fuel: emerging understanding of the adipose tissue,skeletal muscle axis

K. N. Frayn
Abstract The early pioneers in the field of metabolism during exercise such as Lindhard and Krogh understood the importance of fat as a fuel for muscle contraction. But they could not have understood the details of the pathways involved, as neither the metabolic role of adipose tissue nor the transport role of non-esterified fatty acids (NEFA) in the plasma was clearly understood at the time. We now recognize that the onset of muscular contraction coincides with an increase in the delivery of NEFA from adipose tissue, probably coordinated by the sympatho-adrenal system. During light exercise, adipose tissue-derived NEFA make up the majority of the oxidative fuel used by muscle. As exercise is prolonged, the importance of NEFA increases. The onset of exercise is marked by an increased proportion of NEFAs entering ,-oxidation rather than re-esterification and recycling. At moderate intensities of exercise, other sources of fat, potentially plasma- and intramyocellular-triacylglycerol, supplement the supply of plasma NEFA. The delivery of NEFA is augmented by increased adipose tissue blood flow and by other stimuli such as atrial natriuretic peptide. Only during high-intensity exercise is there a failure of adipose tissue to deliver sufficient fatty acids for muscle (which is coupled with an inability of muscle to use them, even when fatty acids are supplied artificially). This limitation of adipose tissue NEFA delivery may reflect some feedback inhibition of lipolysis, perhaps via lactate, or possibly ,-adrenergic inhibition of lipolysis at very high catecholamine concentrations. [source]

Changes in the interaction of resting-state neural networks from adolescence to adulthood

Michael C. Stevens
Abstract This study examined how the mutual interactions of functionally integrated neural networks during resting-state fMRI differed between adolescence and adulthood. Independent component analysis (ICA) was used to identify functionally connected neural networks in 100 healthy participants aged 12,30 years. Hemodynamic timecourses that represented integrated neural network activity were analyzed with tools that quantified system "causal density" estimates, which indexed the proportion of significant Granger causality relationships among system nodes. Mutual influences among networks decreased with age, likely reflecting stronger within-network connectivity and more efficient between-network influences with greater development. Supplemental tests showed that this normative age-related reduction in causal density was accompanied by fewer significant connections to and from each network, regional increases in the strength of functional integration within networks, and age-related reductions in the strength of numerous specific system interactions. The latter included paths between lateral prefrontal-parietal circuits and "default mode" networks. These results contribute to an emerging understanding that activity in widely distributed networks thought to underlie complex cognition influences activity in other networks. Hum Brain Mapp 2009. 2009 Wiley-Liss, Inc. [source]

Using photographs and narratives to contextualise and map the experience of caring for a person with dementia

PGCLT (HE), Penny Hibberd RGN
Aim., To capture the meaning and context of how carers adapt and develop their relationships throughout their caring role. Background., Family carers play a pivotal role in supporting and caring for a person living with dementia at home. To date, the majority of social research on carers has focussed upon the stress and burden that such demands evoke, and limited attention has been paid to locating the carer's own construction of their role with a relationship-centred approach. This paper attempts to build on this emerging understanding. Design., A participative, qualitative study using photographs and supportive narratives to contextualise and map carer's experiences of caring for a person with dementia. The study was conducted in one area of South East England, UK with all necessary ethical permission to conduct the study obtained prior to data collection. Method., Data was obtained between May,June 2008 with nine carers recruited from a not for profit organisation based in the UK. Photographs were taken by participants using a 27-print disposable camera with supporting written narratives provided on six photographs that participants selected to best represent their caring role and relationship. These photographs and supporting text were then shared with other participants in a focus group. Through this process, participants were helped to sort and group the data into narrative themes. Results., From this collaborative process, the group identified four types of caring relationships, these were: recognising (1); transforming (2); stabilising (3); and ,moving on' (4). Photographs and the supporting narratives were used to illustrate each type of relationship that helped to give meaning and shape to everyday life. Conclusion., The four types of caring relationships help nurses and other service providers to understand how carers of people with dementia construct and manage their day-to-day life. Recognition of a carer's personhood needs to be acknowledged in order to promote and support their role throughout the caring trajectory. Relevance to clinical practice., Recognition of the knowledge and skills held by carers of people with dementia can help inform professional decision-making and provide a platform for practice intervention. [source]

Idiosyncratic drug-induced agranulocytosis: Possible mechanisms and management,

Daniel Tesfa
The incidence of drug-induced neutropenia has not changed in the western hemisphere over the last 30 years. Yet, the drug panorama has changed considerably. This implies that host factors may play an intriguing role for this idiosyncratic reaction. The knowledge as to mechanisms for the reaction has advanced with emerging understanding of neutropoiesis and immune regulation. Nonetheless, it is still remarkably difficult to pinpoint why and how a drug causes this unexpected, severe adverse event in a patient. Patient characteristics, e.g. genetics, appear to be keys for better understanding, predictions and prevention. Am. J. Hematol. 2009. 2009 Wiley-Liss, Inc. [source]