Physiologically-obtainable polyphenol exposures modulate reactive oxygen and nitrogen species signaling in the C2C12 model of skeletal muscle ageing.

Age-related frailty is a significant health and social care burden, with limited treatment options. There is a lack of suitable cell culture model for screening large numbers of test compounds to identify those which promote healthy skeletal muscle function. This paper describes the characterization of reactive oxygen and nitrogen species (RONS) signalling changes in young and aged myoblasts and myotubes using C2C12 cells, and the application of aged cultures to assess the effect of dietary polyphenols on RONS signalling. Aged myoblasts and myotubes showed significantly increased reactive oxygen species (p < 0.01 and p < 0.001 respectively), nitric oxide (p < 0.05 for myoblasts and myotubes), and lipid peroxidation (p < 0.05 for myoblasts and myotubes). Nine polyphenols were assessed in aged myoblasts and myotubes using concentrations and incubation times consistent with known pharmacokinetic parameters for these compounds. Although several polyphenols were seen to reduce single markers of RONS signalling, only kaempferol and resveratrol significantly reduced multiple markers in both cell models. Modulation of enzymatic antioxidant activities was assessed as a possible mechanism of action, although superoxide dismutase and catalase activities were significantly reduced in aged (versus young) myotubes (p < 0.01 and p < 0.05 respectively), no effect of polyphenol treatment on these enzyme activities were observed. Overall, this research has shown the utility of the C2C12 model (myoblasts and myotubes) for screening compounds in aged muscle, and that resveratrol and kaempferol (using pharmacokinetically-informed exposures) can modulate RONS signalling in skeletal muscle cells after an acute exposure.

Risk of COVID-19 Disease, Dialysis Unit Attributes, and Infection Control Strategy among London In-Center Hemodialysis Patients.

BACKGROUND AND OBJECTIVES: Patients receiving in-center hemodialysis treatment face unique challenges during the coronavirus disease 2019 (COVID-19) pandemic, specifically the need to attend for treatment that prevents self-isolation. Dialysis unit attributes and isolation strategies that might reduce dialysis center COVID-19 infection rates have not been previously examined. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We explored the role of variables, including community disease burden, dialysis unit attributes (size and layout), and infection control strategies, on rates of COVID-19 among patients receiving in-center hemodialysis in London, United Kingdom, between March 2, 2020 and May 31, 2020. The two outcomes were defined as (1) a positive test for infection or admission with suspected COVID-19 and (2) admission to the hospital with suspected infection. Associations were examined using a discrete time multilevel time-to-event analysis. RESULTS: Data on 5755 patients dialyzing in 51 units were analyzed; 990 (17%) tested positive and 465 (8%) were admitted with suspected COVID-19 between March 2 and May 31, 2020. Outcomes were associated with age, diabetes, local community COVID-19 rates, and dialysis unit size. A greater number of available side rooms and the introduction of mask policies for asymptomatic patients were inversely associated with outcomes. No association was seen with sex, ethnicity, or deprivation indices, nor with any of the different isolation strategies. CONCLUSIONS: Rates of COVID-19 in the in-center hemodialysis population relate to individual factors, underlying community transmission, unit size, and layout.

Implementing neuroimaging and eye tracking methods to assess neurocognitive development of young infants in low- and middle-income countries.

Infants and children in low- and middle-income countries (LMICs) are frequently exposed to a range of environmental risk factors which may negatively affect their neurocognitive development. The mechanisms by which factors such as undernutrition and poverty impact development and cognitive outcomes in early childhood are poorly understood. This lack of knowledge is due in part to a paucity of objective assessment tools which can be implemented across different cultural settings and in very young infants. Over the last decade, technological advances, particularly in neuroimaging, have opened new avenues for research into the developing human brain, allowing us to investigate novel biological associations. This paper presents functional near-infrared spectroscopy (fNIRS), electroencephalography (EEG) and eye tracking (ET) as objective, cross-cultural methods for studying infant neurocognitive development in LMICs, and specifically their implementation in rural Gambia, West Africa. These measures are currently included, as part of a broader battery of assessments, in the Brain Imaging for Global Health (BRIGHT) project, which is developing brain function for age curves in Gambian and UK infants from birth to 24 months of age. The BRIGHT project combines fNIRS, EEG and ET with behavioural, growth, health and sociodemographic measures. The implementation of these measures in rural Gambia are discussed, including methodological and technical challenges that needed to be addressed to ensure successful data acquisition. The aim is to provide guidance to other groups seeking to implement similar methods in their research in other LMICs to better understand associations between environmental risk and early neurocognitive development.

Intranasal oxytocin decreases cross-frequency coupling of neural oscillations at rest.

Recent research has suggested a role for the hormone oxytocin in social cognition and behavior. Administration of intranasal oxytocin modulates multiple brain regions during experimental tasks; however, the neural mechanisms that underscore the changes associated with oxytocin administration are yet to be fully elucidated. In a double-blind placebo controlled design using electroencephalography, the effects of intranasal oxytocin on neural oscillations (delta, theta, alpha, beta) and their coupling during the resting state were examined. Prior work suggested that coupling of slow and fast waves are indicative of the integration of motivational and cognitive processes. While neural oscillations were unaffected by oxytocin relative to placebo administration; oxytocin decreased delta-beta, delta-alpha, theta-alpha, and theta-beta coupling. These findings suggest that one mechanism through which intranasal oxytocin may modulate brain and behavior is through affecting the cross-frequency coupling of neural oscillations, a phenomenon that has been associated with specific cognitive and motivational states.

Intranasal oxytocin and the neural correlates of infant face processing in non-parent women.

Event-related potentials (ERPs) have been widely employed to identify different stages of face processing, with recent research probing the neural dynamics of adult's processing of infant faces. Infant faces represent a salient category of visual stimuli, especially in parents, likely prioritized for processing through activity of the oxytocinergic system. Here we employed a randomized, double-blind, and within-subject crossover study of 24 non-parent women to examine the impact of intranasal oxytocin administration, relative to placebo, on processing infant and adult faces. Our main finding was that, relative to placebo, the P300 ERP elicited by infant faces was greater than the P300 elicited by adult faces in the oxytocin condition. Therefore, oxytocin administration may enhance the allocation of attention towards infant cues, even in non-parent women.

Ab initio calculation of the cross sections for electron impact vibrational excitation of CO via the (2)Π shape resonance.

The stabilization method is used to calculate the complex potential energy curve of the (2)Π state of CO(-) as a function of bond length, with the refinement that separate potentials are determined for p-wave and d-wave attachment and detachment of the excess electron. Using the resulting complex potentials, absolute vibrational excitation cross sections are calculated as a function of electron energy and scattering angle. The calculated cross sections agree well with experiment.