Regional variations in ex-vivo diffusion tensor anisotropy are associated with cardiomyocyte remodeling in rats after left ventricular pressure overload

Background Pressure overload left ventricular (LV) hypertrophy is characterized by increased cardiomyocyte width and ventricle wall thickness, however the regional variation of this remodeling is unclear. Cardiovascular magnetic resonance (CMR) diffusion tensor imaging (DTI) may provide a non-invasive, comprehensive, and geometrically accurate method to detect regional differences in structural remodeling in hypertrophy. We hypothesized that DTI parameters, such as fractional and planar anisotropy, would reflect myocyte remodeling due to pressure overload in a regionally-dependent manner. Methods We investigated the regional distributions of myocyte remodeling in rats with or without transverse aortic constriction (TAC) via direct measurement of myocyte dimensions with confocal imaging of thick tissue sections, and correlated myocyte cross-sectional area and other geometric features with parameters of diffusivity from ex-vivo DTI in the same regions of the same hearts. Results We observed regional differences in several parameters from DTI between TAC hearts and SHAM controls. Consistent with previous studies, helix angles from DTI correlated strongly with those measured directly from histological sections (p < 0.001, R2 = 0.71). There was a transmural gradient in myocyte cross-sectional area in SHAM hearts that was diminished in the TAC group. We also found several regions of significantly altered DTI parameters in TAC LV compared to SHAM, especially in myocyte sheet angle dispersion and planar anisotropy. Among others, these parameters correlated significantly with directly measured myocyte aspect ratios. Conclusions These results show that structural remodeling in pressure overload LV hypertrophy is regionally heterogeneous, especially transmurally, with a greater degree of remodeling in the sub-endocardium compared to the sub-epicardium. Additionally, several parameters derived from DTI correlated significantly with measurements of myocyte geometry from direct measurement in histological sections. We suggest that DTI may provide a non-invasive, comprehensive method to detect regional structural myocyte LV remodeling during disease

Investigation of the fine structure of antihydrogen

At the historic Shelter Island Conference on the Foundations of Quantum Mechanics in 1947, Willis Lamb reported an unexpected feature in the fne structure of atomic hydrogen: a separation of the 2S$_{1/2}$ and 2P$_{1/2}$ states1. The observation of this separation, now known as the Lamb shift, marked an important event in the evolution of modern physics, inspiring others to develop the theory of quantum electrodynamics2–5. Quantum electrodynamics also describes antimatter, but it has only recently become possible to synthesize and trap atomic antimatter to probe its structure. Mirroring the historical development of quantum atomic physics in the twentieth century, modern measurements on anti-atoms represent a unique approach for testing quantum electrodynamics and the foundational symmetries of the standard model. Here we report measurements of the fne structure in the $n=$ 2 states of antihydrogen, the antimatter counterpart of the hydrogen atom. Using optical excitation of the 1S–2P Lyman-α transitions in antihydrogen6 , we determine their frequencies in a magnetic feld of 1 tesla to a precision of 16 parts per billion. Assuming the standard Zeeman and hyperfne interactions, we infer the zero-feld fne-structure splitting (2P$_{1/2}$–2P$_{3/2}$) in antihydrogen. The resulting value is consistent with the predictions of quantum electrodynamics to a precision of 2 per cent. Using our previously measured value of the 1S–2S transition frequency6,7, we fnd that the classic Lamb shift in antihydrogen (2S$_{1/2}$–2P$_{1/2}$ splitting at zero feld) is consistent with theory at a level of 11 per cent. Our observations represent an important step towards precision measurements of the fne structure and the Lamb shift in the antihydrogen spectrum as tests of the charge– parity–time symmetry8 and towards the determination of other fundamental quantities, such as the antiproton charge radius9,10, in this antimatter system

Learning to Eat Vegetables in Early Life: The Role of Timing, Age and Individual Eating Traits

Vegetable intake is generally low among children, who appear to be especially fussy during the pre-school years. Repeated exposure is known to enhance intake of a novel vegetable in early life but individual differences in response to familiarisation have emerged from recent studies. In order to understand the factors which predict different responses to repeated exposure, data from the same experiment conducted in three groups of children from three countries (n = 332) aged 4–38 m (18.9±9.9 m) were combined and modelled. During the intervention period each child was given between 5 and 10 exposures to a novel vegetable (artichoke puree) in one of three versions (basic, sweet or added energy). Intake of basic artichoke puree was measured both before and after the exposure period. Overall, younger children consumed more artichoke than older children. Four distinct patterns of eating behaviour during the exposure period were defined. Most children were “learners” (40%) who increased intake over time. 21% consumed more than 75% of what was offered each time and were labelled “plate-clearers”. 16% were considered “non-eaters” eating less than 10 g by the 5th exposure and the remainder were classified as “others” (23%) since their pattern was highly variable. Age was a significant predictor of eating pattern, with older pre-school children more likely to be non-eaters. Plate-clearers had higher enjoyment of food and lower satiety responsiveness than non-eaters who scored highest on food fussiness. Children in the added energy condition showed the smallest change in intake over time, compared to those in the basic or sweetened artichoke condition. Clearly whilst repeated exposure familiarises children with a novel food, alternative strategies that focus on encouraging initial tastes of the target food might be needed for the fussier and older pre-school children

Developing healthy food preferences in preschool children through taste exposure, sensory learning and nutrition education

Purpose of Review: The present review was undertaken in order to summarize and evaluate recent research investigating taste exposure, sensory learning, and nutrition education interventions for promoting vegetable intake in preschool children. Recent Findings: Overall, taste exposure interventions yielded the best outcomes for increasing vegetable intake in early childhood. Evidence from sensory learning strategies such as visual exposure and experiential learning also show some success. While nutrition education remains the most common approach used in preschool settings, additional elements are needed to strengthen the educational program for increasing vegetable intake. There is a substantial gap in the evidence base to promote vegetable intake in food fussy children. Summary: The present review reveals the relative importance of different intervention strategies for promoting vegetable intake. To strengthen intervention effects for improving vegetable intake in preschool children, future research could consider integrating taste exposure and sensory learning strategies with nutrition education within the preschool curriculum

Granzyme B-Dependent Proteolysis Acts as a Switch to Enhance the Proinflammatory Activity of IL-1α

Granzyme B is a cytotoxic lymphocyte-derived protease that plays a central role in promoting apoptosis of virus-infected target cells, through direct proteolysis and activation of constituents of the cell death machinery. However, previous studies have also implicated granzymes A and B in the production of proinflammatory cytokines, via a mechanism that remains undefined. Here we show that IL-1α is a substrate for granzyme B and that proteolysis potently enhanced the biological activity of this cytokine in vitro as well as in vivo. Consistent with this, compared with full-length IL-1α, granzyme B-processed IL-1α exhibited more potent activity as an immunoadjuvant in vivo. Furthermore, proteolysis of IL-1α within the same region, by proteases such as calpain and elastase, was also found to enhance its biological potency. Thus, IL-1α processing by multiple immune-related proteases, including granzyme B, acts as a switch to enhance the proinflammatory properties of this cytokin