Micro to macro scale anatomical analysis of the human hippocampal arteries with synchrotron hierarchical phase-contrast tomography.

PURPOSE: To date, no non-invasive imaging modality has been employed to profile the structural intricacies of the hippocampal arterial microvasculature in humans. We hypothesised that synchrotron-based imaging of the human hippocampus would enable precise characterisation of the arterial microvasculature. METHODS: Two preserved human brains from, a 69-year-old female and a 63-year-old male body donors were imaged using hierarchical phase-contrast tomography (HiP-CT) with synchrotron radiation at multiple voxel resolutions from 25.08 µm down to 2.45 µm. Subsequent manual and semi-automatic artery segmentation were performed followed by morphometric analyses. These data were compared to published data from alternative methodologies. RESULTS: HiP-CT made it possible to segment in context the arterial architecture of the human hippocampus. Our analysis identified anterior, medial and posterior hippocampal arteries arising from the P2 segment of the posterior cerebral artery on the image slices. We mapped arterial branches with external diameters greater than 50 µm in the hippocampal region. We visualised vascular asymmetry and quantified arterial structures with diameters as small as 7 µm. CONCLUSIONS: Through the application of HiP-CT, we have provided the first imaging visualisation and quantification of the arterial system of the human hippocampus at high resolution in the context of whole brain imaging. Our results bridge the gap between anatomical and histological scales.

Perceptions of climate change and associated health impacts among communities in Johor River Basin, Malaysia.

INTRODUCTION: As climate change is threatening every region of the world, extreme weather events resultant of global warming is occurring at increasing rate and scale in Malaysia. Weather-related disasters such as flood and haze pose critical challenges to the infrastructure and raise public health concerns in the country, especially when main economic sectors rely heavily on climate variability. Public perception on environmental issues is crucial for development of pro-environmental policies. Among studies conducted to understand public awareness regarding global warming, reports of perception on the health impacts were very limited. Taking this limitation into account, this study was designed to examine the perception on the health impacts of climate change among the diverse communities living in the Johor River Basin. MATERIALS AND METHODS: The cross-sectional study was conducted through cloud-data-based digital questionnaires completed by randomly selected residents in the Johor River Basin (n=647). Data was analysed with descriptive statistics using SPSS 27 (IBM®) Software. Comparisons between indigenous and non-indigenous communities were performed using Chi square analysis. RESULTS: Respondents in this study consisted of indigenous people (n=79) and non-indigenous people (n=568). Indigenous respondents generally perceived more frequent occurrence of extreme weather events in the next 20 years, even for the phenomena unfamiliar in Malaysian settings. All respondents showed similar concerns for health impacts of global warming, although the non-indigenous respondents perceived the risk further into the future (25 years) compared to the indigenous respondents who perceived current or imminent (<10 years) risks. Intense concerns for self, children, family members and community were shown by nearly all indigenous respondents (97-99%), while the non-indigenous people in this study expressed stronger concerns at country level and for future generations. During the last haze episode, most indigenous respondents (85%) did not notice any change in air quality nor discomfort among family members, in contrast 70% of the nonindigenous respondents claimed to have suffered from breathing problems themselves as well as others in the family. All respondents were concerned about air quality in their surroundings, indigenous people were concerned for the near future (<10 years), and non-indigenous people were concerned for the next 25 years. CONCLUSION: In this study, respondents were generally concerned about the health impacts of unimpeded global warming. There was significant difference in perceptions between indigenous and non-indigenous respondents. The findings were useful, complemented with further studies, to improve understanding of public awareness and to help develop relevant education programmes accessible for wider audience.

Sun-related knowledge and practices in Irish construction and agricultural workers.

BACKGROUND: Agricultural and construction workers spend much of their work time outdoors and have higher risks of developing skin cancer when compared to indoor workers. However, there is limited research on ultraviolet radiation (UVR) exposure knowledge, sun safety practices and constraints within these occupational groups in Ireland. AIMS: This study aimed to examine self-reported time spent outdoors in a sample of Irish agricultural and construction workers; to describe and compare UVR exposure knowledge, safety practices and perceived constraints in both occupational groups, and to assess the association of demographic, personal and occupational factors with sun-related knowledge, practices and perceived constraints. METHODS: Agricultural workers (n = 154) and construction workers (n = 467) completed a questionnaire, which measured solar UVR exposure knowledge, safety practices, and perceived constraints to sun personal protective equipment and sunscreen use in addition to demographic, personal, and workplace characteristics. Mann-Whitney and Kruskal-Wallis tests were used to examine differences in knowledge, practices and perceived constraints by these characteristics. RESULTS: Both groups spend a significant proportion of their working week outdoors (25 hours per week on average). Although participation in sun safety training was high for both groups, UVR exposure knowledge and sunscreen use were low, and annual rates of reported sunburn were high. Knowledge, practices and perceived constraints also differed significantly according to demographic, personal, occupational and workplace characteristics. CONCLUSIONS: In addition to training by employers and advisory groups, interventions are required to address perceived barriers that impede the uptake and usage of control measures that can lower risk.

Improved filters for angular filter refractometry.

Angular filter refractometry is an optical diagnostic that measures the absolute contours of a line-integrated density gradient by placing a filter with alternating opaque and transparent zones in the focal plane of a probe beam, which produce corresponding alternating light and dark regions in the image plane. Identifying transitions between these regions with specific zones on the angular filter (AF) allows the line-integrated density to be determined, but the sign of the density gradient at each transition is degenerate and must be broken using other information about the object plasma. Additional features from diffraction in the filter plane often complicate data analysis. In this paper, we present an improved AF design that uses a stochastic pixel pattern with a sinusoidal radial profile to minimize unwanted diffraction effects in the image caused by the sharp edges of the filter bands. We also present a technique in which a pair of AFs with different patterns on two branches of the same probe beam can be used to break the density gradient degeneracy. Both techniques are demonstrated using a synthetic diagnostic and data collected on the OMEGA EP (extended performance) laser.

Patient-reported outcomes of laparoscopic magnetic sphincter augmentation for gastro-oesophageal reflux disease.

INTRODUCTION: Gastro-oesophageal reflux disease (GORD) is a chronic progressive disease, associated with substantial clinical and economic burden. Proton pump inhibitors (PPIs) are considered first-line treatment; however, there are concerns around the long-term impact of their usage. Surgical treatment with Nissen fundoplication can be considered but, because of the potential side effects, few patients undergo surgery and there remains a substantial therapeutic gap within the current treatment pathway. Laparoscopic magnetic sphincter augmentation (MSA) using the LINX® device is an alternative surgical approach. METHODS: The objective of this study was to investigate patient-reported outcomes following laparoscopic MSA surgery using the LINX® device in a UK setting. A retrospective questionnaire obtained data regarding postoperative symptoms, medication use and patient satisfaction. RESULTS: Out of 131 patients surveyed, 97 responses were received, with a minimum follow-up time of 1 year. In those who reported heartburn and regurgitation preoperatively, improvement was reported in 93% (84/90) and 90% (86/96) of patients, respectively. Eighty-eight per cent (73/83) of patients were able to completely stop or reduce their medication by at least 75%. Seventy-seven per cent (73/95) of patients were "very satisfied" or "satisfied". CONCLUSIONS: This study is the first to present patient-reported outcomes of MSA using the LINX® device for patients with GORD in the UK. It demonstrates that the device has favourable outcomes and could effectively bridge the current therapeutic gap that exists between PPI medication and Nissen fundoplication.

Multidimensional Analysis of the Adult Human Heart in Health and Disease using Hierarchical Phase-Contrast Tomography (HiP-CT).

Cardiovascular diseases (CVDs) are a leading cause of death worldwide. Current clinical imaging modalities provide resolution adequate for diagnosis but are unable to provide detail of structural changes in the heart, across length-scales, necessary for understanding underlying pathophysiology of disease. Hierarchical Phase-Contrast Tomography (HiP-CT), using new (4th) generation synchrotron sources, potentially overcomes this limitation, allowing micron resolution imaging of intact adult organs with unprecedented detail. In this proof of principle study (n=2), we show the utility of HiP-CT to image whole adult human hearts ex-vivo: one 'control' without known cardiac disease and one with multiple known cardiopulmonary pathologies. The resulting multiscale imaging was able to demonstrate exemplars of anatomy in each cardiac segment along with novel findings in the cardiac conduction system, from gross (20 um/voxel) to cellular scale (2.2 um/voxel), non-destructively, thereby bridging the gap between macroscopic and microscopic investigations. We propose that the technique represents a significant step in virtual autopsy methods for studying structural heart disease, facilitating research into abnormalities across scales and age-groups. It opens up possibilities for understanding and treating disease; and provides a cardiac 'blueprint' with potential for in-silico simulation, device design, virtual surgical training, and bioengineered heart in the future.

The genesis of the PM-JAY health insurance scheme in India: technical and political elements influencing a national reform towards universal health coverage.

Many countries are using health insurance to advance progress towards universal health coverage (UHC). India launched the Pradhan Mantri Jan Arogya Yojana (PM-JAY) health insurance scheme in 2018. We examine the political economy context around PM-JAY policy formulation, by examining the perspectives of policy stakeholders shaping decisions around the reform. More specifically, we focus on early policy design at the central (national) level. We use a framework on the politics of UHC reform proposed by Fox and Reich (The politics of universal health coverage in low- and middle-income countries: A framework for evaluation and action. J. Health Polit. Policy Law 2015;40:1023-1060), to categorize the reform into phases and examine the interactions between actors, institutions, interests, ideas and ideology which shaped reform decisions. We interviewed 15 respondents in Delhi between February and April 2019, who were either closely associated with the reform process or subject experts. The ruling centre-right government introduced PM-JAY shortly before national elections, drawing upon policy legacies from prior and state insurance schemes. Empowered policy entrepreneurs within the government focused discourse around ideas of UHC and strategic purchasing, and engaged in institution building leading to the creation of the National Health Authority and State Health Agencies through policy directives, thereby expanding state infrastructural and institutional power for insurance implementation. Indian state inputs were incorporated in scheme design features like mode of implementation, benefit package and provider network, while features like the coverage amount, portability of benefits and branding strategy were more centrally driven. These balanced negotiations opened up political space for a cohesive, central narrative of the reform and facilitated adoption. Our analysis shows that the PM-JAY reform focused on bureaucratic rather than ideological elements and that technical compromises and adjustments accommodating the interests of states enabled the political success of policy formulation. Appreciating these politics, power and structural issues shaping PM-JAY institutional design will be important to understand how PM-JAY is implemented and how it advances UHC in India.

Measurement of Magnetic Cavitation Driven by Heat Flow in a Plasma.

We describe the direct measurement of the expulsion of a magnetic field from a plasma driven by heat flow. Using a laser to heat a column of gas within an applied magnetic field, we isolate Nernst advection and show how it changes the field over a nanosecond timescale. Reconstruction of the magnetic field map from proton radiographs demonstrates that the field is advected by heat flow in advance of the plasma expansion with a velocity v_{N}=(6±2)×10^{5} m/s. Kinetic and extended magnetohydrodynamic simulations agree well in this regime due to the buildup of a magnetic transport barrier.

The UHRF1 protein is a key regulator of retrotransposable elements and innate immune response to viral RNA in human cells.

While epigenetic mechanisms such as DNA methylation and histone modification are known to be important for gene suppression, relatively little is still understood about the interplay between these systems. The UHRF1 protein can interact with both DNA methylation and repressive chromatin marks, but its primary function in humans has been unclear. To determine what that was, we first established stable UHRF1 knockdowns (KD) in normal, immortalized human fibroblasts using targeting shRNA, since CRISPR knockouts (KO) were lethal. Although these showed a loss of DNA methylation across the whole genome, transcriptional changes were dominated by the activation of genes involved in innate immune signalling, consistent with the presence of viral RNA from retrotransposable elements (REs). We confirmed using mechanistic approaches that 1) REs were demethylated and transcriptionally activated; 2) this was accompanied by activation of interferons and interferon-stimulated genes and 3) the pathway was conserved across other adult cell types. Restoring UHRF1 in either transient or stable KD systems could abrogate RE reactivation and the interferon response. Notably, UHRF1 itself could also re-impose RE suppression independent of DNA methylation, but not if the protein contained point mutations affecting histone 3 with trimethylated lysine 9 (H3K9me3) binding. Our results therefore show for the first time that UHRF1 can act as a key regulator of retrotransposon silencing independent of DNA methylation.

Preparation of large biological samples for high-resolution, hierarchical, synchrotron phase-contrast tomography with multimodal imaging compatibility.

Imaging across different scales is essential for understanding healthy organ morphology and pathophysiological changes. The macro- and microscale three-dimensional morphology of large samples, including intact human organs, is possible with X-ray microtomography (using laboratory or synchrotron sources). Preparation of large samples for high-resolution imaging, however, is challenging due to limitations such as sample shrinkage, insufficient contrast, movement of the sample and bubble formation during mounting or scanning. Here, we describe the preparation, stabilization, dehydration and mounting of large soft-tissue samples for X-ray microtomography. We detail the protocol applied to whole human organs and hierarchical phase-contrast tomography at the European Synchrotron Radiation Facility, yet it is applicable to a range of biological samples, including complete organisms. The protocol enhances the contrast when using X-ray imaging, while preventing sample motion during the scan, even with different sample orientations. Bubbles trapped during mounting and those formed during scanning (in the case of synchrotron X-ray imaging) are mitigated by multiple degassing steps. The sample preparation is also compatible with magnetic resonance imaging, computed tomography and histological observation. The sample preparation and mounting require 24-36 d for a large organ such as a whole human brain or heart. The preparation time varies depending on the composition, size and fragility of the tissue. Use of the protocol enables scanning of intact organs with a diameter of 150 mm with a local voxel size of 1 µm. The protocol requires users with expertise in handling human or animal organs, laboratory operation and X-ray imaging.

Anti-inflammatory therapy enables robot-actuated regeneration of aged muscle.

Robot-actuated mechanical loading (ML)-based therapies ("mechanotherapies") can promote regeneration after severe skeletal muscle injury, but the effectiveness of such approaches during aging is unknown and may be influenced by age-associated decline in the healing capacity of skeletal muscle. To address this knowledge gap, this work used a noninvasive, load-controlled robotic device to impose highly defined tissue stresses to evaluate the age dependence of ML on muscle repair after injury. The response of injured muscle to robot-actuated cyclic compressive loading was found to be age sensitive, revealing not only a lack of reparative benefit of ML on injured aged muscles but also exacerbation of tissue inflammation. ML alone also disrupted the normal regenerative processes of aged muscle stem cells. However, these negative effects could be reversed by introducing anti-inflammatory therapy alongside ML application, leading to enhanced skeletal muscle regeneration even in aged mice.

Epigenetic effects of folate and related B vitamins on brain health throughout life: Scientific substantiation and translation of the evidence for health improvement strategies.

Suboptimal status of folate and/or interrelated B vitamins (B12 , B6 and riboflavin) can perturb one-carbon metabolism and adversely affect brain development in early life and brain function in later life. Human studies show that maternal folate status during pregnancy is associated with cognitive development in the child, whilst optimal B vitamin status may help to prevent cognitive dysfunction in later life. The biological mechanisms explaining these relationships are not clear but may involve folate-related DNA methylation of epigenetically controlled genes related to brain development and function. A better understanding of the mechanisms linking these B vitamins and the epigenome with brain health at critical stages of the lifecycle is necessary to support evidence-based health improvement strategies. The EpiBrain project, a transnational collaboration involving partners in the United Kingdom, Canada and Spain, is investigating the nutrition-epigenome-brain relationship, particularly focussing on folate-related epigenetic effects in relation to brain health outcomes. We are conducting new epigenetics analysis on bio-banked samples from existing well-characterised cohorts and randomised trials conducted in pregnancy and later life. Dietary, nutrient biomarker and epigenetic data will be linked with brain outcomes in children and older adults. In addition, we will investigate the nutrition-epigenome-brain relationship in B vitamin intervention trial participants using magnetoencephalography, a state-of-the-art neuroimaging modality to assess neuronal functioning. The project outcomes will provide an improved understanding of the role of folate and related B vitamins in brain health, and the epigenetic mechanisms involved. The results are expected to provide scientific substantiation to support nutritional strategies for better brain health across the lifecycle.

Nonlinear ablative Rayleigh-Taylor instability: Increased growth due to self-generated magnetic fields.

The growth rate of the nonlinear ablative Rayleigh-Taylor (RT) instability is enhanced by magnetic fields self-generated by the Biermann battery mechanism; a scaling for this effect with perturbation height and wavelength is proposed and validated with extended-magnetohydrodynamic simulations. The magnetic flux generation rate around a single RT spike is found to scale with the spike height. The Hall parameter, which quantifies electron magnetization, is found to be strongly enhanced for short-wavelength spikes due to Nernst compression of the magnetic field at the spike tip. The impact of the magnetic field on spike growth is through both the suppressed thermal conduction into the unstable spike and the Righi-Leduc heat flow deflecting heat from the spike tip to the base. Righi-Leduc is found to be the dominant effect for small Hall parameters, while suppressed thermal conduction dominates for large Hall parameters. These results demonstrate the importance of considering magnetic fields in all perturbed inertial confinement fusion hot spots.

Validity of the DSM-5 craving criterion for alcohol, tobacco, cannabis, cocaine, heroin, and non-prescription use of prescription painkillers (opioids).

BACKGROUND: Although the DSM-5 was adopted in 2013, the validity of the new substance use disorder (SUD) diagnosis and craving criterion has not been investigated systematically across substances. METHODS: Adults (N = 588) who engaged in binge drinking or illicit drug use and endorsed at least one DSM-5 SUD criterion were included. DSM-5 SUD criteria were assessed for alcohol, tobacco, cannabis, cocaine, heroin, and opioids. Craving was considered positive if "wanted to use so badly that could not think of anything else" (severe craving) or "felt a very strong desire or urge to use" (moderate craving) was endorsed. Baseline information on substance-related variables and psychopathology was collected, and electronic daily assessment queried substance use for the following 90 days. For each substance, logistic regression estimated the association between craving and validators, i.e. variables expected to be related to craving/SUD, and whether association with the validators differed for DSM-5 SUD diagnosed with craving as a criterion v. without. RESULTS: Across substances, craving was associated with most baseline validators (p values<0.05); neither moderate nor severe craving consistently showed greater associations. Baseline craving predicted subsequent use [odds ratios (OR): 4.2 (alcohol) - 234.3 (heroin); p's ⩽ 0.0001], with stronger associations for moderate than severe craving (p's < 0.05). Baseline DSM-5 SUD showed stronger associations with subsequent use when diagnosed with craving than without (p's < 0.05). CONCLUSION: The DSM-5 craving criterion as operationalized in this study is valid. Including craving improves the validity of DSM-5 SUD diagnoses, and clinical relevance, since craving may cause impaired control over use and development and maintenance of SUD.

Reading a preoperative CT scan to guide complex abdominal wall reconstructive surgery.

Computed tomography (CT) scanning is the imaging modality of choice when planning the overall management and operative approach to complex abdominal wall hernias. Despite its availability and well-recognised benefits there are no guidelines or recommendations regarding how best to read or report such scans for this application. In this paper we aim to outline an approach to interpreting preoperative CT scans in abdominal wall reconstruction (AWR). This approach breaks up the interpretive process into 4 steps-concentrating on the hernia or hernias, any complicating features of the hernia(s), the surrounding soft tissues and the abdominopelvic cavity as a whole-and was developed as a distillation of the authors' collective experience. We describe the key features that should be looked for at each of the four steps and the rationale for their inclusion.

Investigation of the gut microbiome, bile acid composition and host immunoinflammatory response in a model of azoxymethane-induced colon cancer at discrete timepoints.

BACKGROUND: Distinct sets of microbes contribute to colorectal cancer (CRC) initiation and progression. Some occur due to the evolving intestinal environment but may not contribute to disease. In contrast, others may play an important role at particular times during the tumorigenic process. Here, we describe changes in the microbiota and host over the course of azoxymethane (AOM)-induced tumorigenesis. METHODS: Mice were administered AOM or PBS and were euthanised 8, 12, 24 and 48 weeks later. Samples were analysed using 16S rRNA gene sequencing, UPLC-MS and qRT-PCR. RESULTS: The microbiota and bile acid profile showed distinct changes at each timepoint. The inflammatory response became apparent at weeks 12 and 24. Moreover, significant correlations between individual taxa, cytokines and bile acids were detected. One co-abundance group (CAG) differed significantly between PBS- and AOM-treated mice at week 24. Correlation analysis also revealed significant associations between CAGs, bile acids and the bile acid transporter, ASBT. Aberrant crypt foci and adenomas were first detectable at weeks 24 and 48, respectively. CONCLUSION: The observed changes precede host hyperplastic transformation and may represent early therapeutic targets for the prevention or management of CRC at specific timepoints in the tumorigenic process.

X-ray imaging and radiation transport effects on cylindrical implosions.

Magnetization of inertial confinement implosions is a promising means of improving their performance, owing to the potential reduction of energy losses within the target and mitigation of hydrodynamic instabilities. In particular, cylindrical implosions are useful for studying the influence of a magnetic field, thanks to their axial symmetry. Here, we present experimental results from cylindrical implosions on the OMEGA-60 laser using a 40-beam, 14.5 kJ, 1.5 ns drive and an initial seed magnetic field of B0 = 30 T along the axes of the targets, compared with reference results without an imposed B-field. Implosions were characterized using time-resolved x-ray imaging from two orthogonal lines of sight. We found that the data agree well with magnetohydrodynamic simulations, once radiation transport within the imploding plasma is considered. We show that for a correct interpretation of the data in these types of experiments, explicit radiation transport must be taken into account.

Separating the components of an abdominal wall fellowship.

Complex abdominal wall reconstruction is an emerging subspecialty yet, despite the abundance of abdominal wall hernias requiring treatment and the increasing complexity of this type of surgery, there are few opportunities for surgeons to gain subspecialist training in this field. In this paper we discuss the need for focused training in complex abdominal wall reconstruction, outline some of the problems that may be hindering the availability of such opportunities and propose potential solutions to these issues.

Increased Ion Temperature and Neutron Yield Observed in Magnetized Indirectly Driven D_{2}-Filled Capsule Implosions on the National Ignition Facility.

The application of an external 26 Tesla axial magnetic field to a D_{2} gas-filled capsule indirectly driven on the National Ignition Facility is observed to increase the ion temperature by 40% and the neutron yield by a factor of 3.2 in a hot spot with areal density and temperature approaching what is required for fusion ignition [1]. The improvements are determined from energy spectral measurements of the 2.45 MeV neutrons from the D(d,n)^{3}He reaction, and the compressed central core B field is estimated to be ∼4.9 kT using the 14.1 MeV secondary neutrons from the D(T,n)^{4}He reactions. The experiments use a 30 kV pulsed-power system to deliver a ∼3 µs current pulse to a solenoidal coil wrapped around a novel high-electrical-resistivity AuTa_{4} hohlraum. Radiation magnetohydrodynamic simulations are consistent with the experiment.