Social support mediates the relationships between extraversion, neuroticism, and cognitive function in older adults.

OBJECTIVES: We supplement existing findings on a link between social support and cognitive function in later life by considering the role of personality as an antecedent to both, and of social support as a mediator of the link between personality and cognitive function. STUDY DESIGN: An observational cohort study. METHODS: We evaluated social support using the Lubben Social Network Scale, across 624 adults aged over 60 years, and investigated this measure as a mediator of the relationships between extraversion and neuroticism at baseline 2007-2009, and cognitive function at follow-up, 2 years later. A half-longitudinal mediation design, within a structural equation modelling framework, was used. RESULTS: There was a direct effect of extraversion, such that lower levels were related to higher scores of cognitive function. There was no significant direct effect of neuroticism on cognitive function at follow-up. Social support partially mediated the paths between both extraversion and neuroticism and cognitive function at follow-up. Decomposing the mediation effects by using social support subscales (measuring support from friends, relatives and neighbours) showed meaningful indirect effects for both predictors. CONCLUSION: Results suggest that social support may offer a target for interventions for cognitively at-risk older adults and add to the existing empirical evidence describing the link between personality and cognitive function.

Increasing the quantitative bandwidth of NMR measurements.

The frequency range of quantitative NMR is increased from tens to hundreds of kHz by a new pulse sequence, CHORUS. It uses chirp pulses to excite uniformly over very large bandwidths, yielding accurate integrals even for nuclei such as (19)F that have very wide spectra.

The effects of high-fat feeding on physical function and skeletal muscle extracellular matrix.

Skeletal muscle extracellular matrix (ECM) remodelling has been proposed as a feature of the pathogenic milieu associated with obesity and metabolic dysfunction. Whether muscle ECM is associated with impaired physical function in obese conditions is unknown. C57BL/6 mice were fed a high-fat diet (HFD) or chow for 5, 10 and 25 weeks. Non-invasive physiological tests (hang wire, hang mesh and grip strength) to assess neuromuscular function and motor co-ordination were performed. Genes related to ECM structure (COL1, COL3, COL6A2, SPARC), growth factors (TGFB1, TGFB2, CTGF, VEGF) and muscle function (DMD (Dp147), CPN3, DAG1) were measured in gastrocnemius muscle using real-time PCR and COL1, 3 and 6 protein were measured by western immunoblot. Compared with chow, HFD mice had two to six-fold lower muscle strength (hang wire test; raw data and multiplied by body weight) at all time-points (P<0.001) and two-fold lower hang mesh and grip strength at 10 weeks (P<0.05). At 5 weeks, COL1, COL3 and COL6 gene expression, but not protein levels were three to eight-fold lower in HFD compared with chow. In the HFD group at 5 weeks, greater COL3 and 6 gene expression were associated with poorer hang wire performance. For the first time, our results demonstrate links between muscle ECM structure and physical function in obesity.

Utility of 111In-labelled leukocytes in patients completing high-dose interleukin-2 therapy: a pilot study.

Interleukin-2 (IL-2) therapy has resulted in modest response rates in patients with renal carcinoma and melanoma, but few reproducible pre- or post-treatment parameters have been associated with response, and tumour localization with lymphokine-activated killer cells has only occasionally been demonstrated. Eight patients (seven with renal carcinoma and one with melanoma) treated on a protocol with chronic indomethacin and ranitidine with three courses of continuous infusion of IL-2 had peripheral blood leukocytes withdrawn 12-36 h after completion of IL-2 therapy, labelled with 111In tropolone and reinjected. Images were taken at 4 and 20 h after reinjection. Three of these patients achieved objective responses to therapy, but none demonstrated uptake of radioisotope-labelled leukocytes in known tumour-bearing areas. Two nonresponding patients (one renal carcinoma, one melanoma) demonstrated uptake in all known tumour areas; one further nonresponding patient demonstrated uptake in the region of a femoral metastasis, but not in other bulky areas of disease. No correlation between scan uptake, and leukocyte subsets could be demonstrated. Although occasional patients demonstrate tumoural accumulations of 111In-labelled leukocytes after completion of therapy with IL-2, this does not appear to be associated with response.