Examining mental health and autonomic function as putative mediators of the relationship between sleep and trajectories of cognitive function: findings from the Irish longitudinal study on ageing (TILDA).

OBJECTIVES: This study investigates the mediating roles of autonomic function and mental health in the association between sleep and cognitive decline in adults aged 50 and above. METHOD: A total of 2,697 participants with observations on sleep and mediators at baseline and repeated measures of cognitive function (MMSE) were included. Clusters of individuals with similar cognitive trajectories (high-stable, mid-stable and low-declining) were identified. Multinomial logistic regressions were used to estimate the likelihood of membership to each trajectory group based on sleep duration and disturbance. Finally, mediation analysis tested potential mediating effects of autonomic function and mental health underpinning the sleep-cognition relationship. RESULTS: Short (p = .028), long (p =.019), and disturbed sleep (p =.008) increased the likelihood of a low-declining cognitive trajectory. Mental health measures fully attenuated relationships between cognitive decline and short or disturbed sleep but not long sleep. No autonomic function mediation was observed. CONCLUSION: Older adults with short or disturbed sleep are at risk of cognitive decline due to poor mental health. Individuals with long sleep are also at risk, however, the acting pathways remain to be identified. These outcomes have clinical implications, potentially identifying intervention strategies targeting mental health and sleep as prophylactic measures against dementia.

The Emerging Role and Clinical Applications of Morphomics in Diagnostic Imaging.

Analytic morphomics refers to the accurate measurement of specific biological markers of human body composition in diagnostic medical imaging. The increasing prevalence of disease processes that alter body composition including obesity, cachexia, and sarcopenia has generated interest in specific targeted measurement of these metrics to possibly prevent or reduce negative health outcomes. Typical morphomic measurements include the area and density of muscle, bone, vascular calcification, visceral fat, and subcutaneous fat on a specific validated axial level in the patient's cross-sectional diagnostic imaging. A distinct advantage of these measurements is that they can be made retrospectively and opportunistically with pre-existing datasets. We provide a narrative review of the current state of art in morphomics, but also consider some potential future directions for this exciting field. Imaging based quantitative assessment of body composition has enormous potential across the breadth and scope of modern clinical practice. From risk stratification to treatment planning, and outcome assessment, all can be enhanced with the use of analytic morphomics. Moreover, it is likely that many new opportunities for personalized medicine will emerge as the field evolves. As radiologists, embracing analytic morphomics will enable us to contribute added value in the care of every patient.

Paediatric Thoracic Imaging in Cystic Fibrosis in the Era of Cystic Fibrosis Transmembrane Conductance Regulator Modulation.

Cystic fibrosis (CF) is one of the most common progressive life-shortening genetic conditions worldwide. Ground-breaking translational research has generated therapies that target the primary cystic fibrosis transmembrane conductance regulator (CFTR) defect, known as CFTR modulators. A crucial aspect of paediatric CF disease is the development and progression of irreversible respiratory disease in the absence of clinical symptoms. Accurate thoracic diagnostics have an important role to play in this regard. Chest radiographs are non-specific and insensitive in the context of subtle changes in early CF disease, with computed tomography (CT) providing increased sensitivity. Recent advancements in imaging hardware and software have allowed thoracic CTs to be acquired in paediatric patients at radiation doses approaching that of a chest radiograph. CFTR modulators slow the progression of CF, reduce the frequency of exacerbations and extend life expectancy. In conjunction with advances in CT imaging techniques, low-dose thorax CT will establish a central position in the routine care of children with CF. International guidelines regarding the choice of modality and timing of thoracic imaging in children with CF are lagging behind these rapid technological advances. The continued progress of personalised medicine in the form of CFTR modulators will promote the emergence of personalised radiological diagnostics.

Declining Corticosteroid Use for Inflammatory Bowel Disease Across Alberta: A Population-Based Cohort Study.

Background and Aims: Corticosteroid-free remission is a primary treatment goal in IBD which may be achieved with greater use of anti-TNF therapy. We defined temporal trends of corticosteroid use, anti-TNF use, hospitalization and surgery in a prevalent IBD cohort within the province of Alberta, Canada. Methods: Health administrative data were used to identify medication dispensing, hospitalizations and surgery in individuals with IBD from 2010 to 2015. Temporal trends were calculated using log-binomial regression for medications and log-linear models for hospitalizations and surgery rates. Analyses were stratified based on geographic location. Results: Of 28890 individuals with IBD, 50.3% had Crohn's disease. One in six individuals (15.45%) were dispensed a corticosteroid. Corticosteroid use decreased in both metropolitan areas (AAPC -20.08%, 95% CI: -21.78 to -18.04) and non-metropolitan areas (AAPC -18.14%, 95% CI: -20.78 to -18.04) with a similar pattern for corticosteroid dependence. Corticosteroid dependence was more prevalent in UC vs. CD (P < 0.05), and in the pediatric IBD cohort (13.45) compared to the adult (8.89) and elderly (7.54) cohorts (per 100 prevalent population, P < 0.001). The proportion of individuals dispensed an anti-TNF increased over the study period (AAPC 12.58%, 95% CI: 11.56 to 13.61). Significantly more non-metropolitan versus metropolitan residing individuals were hospitalized for any reason, for an IBD-related, or IBD-specific indication (all P < 0.001) though the proportion requiring IBD surgery was similar between groups. Conclusions: An increase in anti-TNF use corresponded to a decline in corticosteroid use and dependence in those with IBD. Inequities in IBD care still exist based on location and age.

Development and implementation of an ultralow-dose CT protocol for the assessment of cerebrospinal shunts in adult hydrocephalus.

BACKGROUND: Cerebrospinal fluid shunts in the treatment of hydrocephalus, although associated with clinical benefit, have a high failure rate with repeat computed tomography (CT) imaging resulting in a substantial cumulative radiation dose. Therefore, we sought to develop a whole-body ultralow-dose (ULD) CT protocol for the investigation of shunt malfunction and compare it with the reference standard, plain radiographic shunt series (PRSS). METHODS: Following ethical approval, using an anthropomorphic phantom and a human cadaveric ventriculoperitoneal shunt model, a whole-body ULD-CT protocol incorporating two iterative reconstruction (IR) algorithms, pure IR and hybrid IR, including 60% filtered back projection and 40% IR was evaluated in 18 adult patients post new shunt implantation or where shunt malfunction was suspected. Effective dose (ED) and image quality were analysed. RESULTS: ULD-CT permitted a 36% radiation dose reduction (median ED 0.16 mSv, range 0.07-0.17, versus 0.25 mSv (0.06-1.69 mSv) for PRSS (p = 0.002). Shunt visualisation in the thoracoabdominal cavities was improved with ULD-CT with pure IR (p = 0.004 and p = 0.031, respectively) and, in contrast to PRSS, permitted visualisation of the entire shunt course (p < 0.001), the distal shunt entry point and location of the shunt tip in all cases. For shunt complications, ULD-CT had a perfect specificity. False positives (3/22, 13.6%) were observed with PRSS. CONCLUSIONS: At a significantly reduced radiation dose, whole body ULD-CT with pure IR demonstrated diagnostic superiority over PRSS in the evaluation of cerebrospinal fluid shunt malfunction.

Bridging the divide between medical school and clinical practice: identification of six key learning outcomes for an undergraduate preparatory course in radiology.

BACKGROUND: There exists a significant divide between what is learnt in medical school and subsequently what is required to practice medicine effectively. Despite multiple strategies to remedy this discordance, the problem persists. Here, we describe the identification of a comprehensive set of learning outcomes for a preparation for practice course in radiology. METHODS: Assessment of interns' readiness to interact with the radiology department was conducted using a national survey of both interns and radiologists. In parallel, group concept mapping (GCM) which involves a combination of qualitative and quantitative techniques was used to identify the shared understanding of participants from a diverse range of medical specialties regarding what topics should be included in an intern preparatory course for interacting with the radiology department. RESULTS: The survey demonstrated that most interns and radiologists felt that undergraduate medical training did not prepare interns to interact with the radiology department. GCM identified six learning outcomes that should be targeted when designing a preparatory module: requesting investigations; clinical decision support; radiology department IT and communication; adverse reactions and risks; interpretation of radiology results and urgent imaging. The thematic clusters from the group concept mapping corroborated the deficiencies identified in the national survey. CONCLUSION: We have identified six key learning outcomes that should be included in a preparation for practice module in radiology. Future courses targeting these thematic clusters may facilitate a smoother transition from theory to practice for newly graduated doctors.

Expanded potential stem cell media as a tool to study human developmental hematopoiesis in vitro.

Pluripotent stem cell (PSC) differentiation in vitro represents a powerful and tractable model to study mammalian development and an unlimited source of cells for regenerative medicine. Within hematology, in vitro PSC hematopoiesis affords novel insights into blood formation and represents an exciting potential approach to generate hematopoietic and immune cell types for transplantation and transfusion. Most studies to date have focused on in vitro hematopoiesis from mouse PSCs and human PSCs. However, differences in mouse and human PSC culture protocols have complicated the translation of discoveries between these systems. We recently developed a novel chemical media formulation, expanded potential stem cell medium (EPSCM), that maintains mouse PSCs in a unique cellular state and extraembryonic differentiation capacity. Herein, we describe how EPSCM can be directly used to stably maintain human PSCs. We further demonstrate that human PSCs maintained in EPSCM can spontaneously form embryoid bodies and undergo in vitro hematopoiesis using a simple differentiation protocol, similar to mouse PSC differentiation. EPSCM-maintained human PSCs generated at least two hematopoietic cell populations, which displayed distinct transcriptional profiles by RNA-sequencing (RNA-seq) analysis. EPSCM also supports gene targeting using homologous recombination, affording generation of an SPI1 (PU.1) reporter PSC line to study and track in vitro hematopoiesis. EPSCM therefore provides a useful tool not only to study pluripotency but also hematopoietic cell specification and developmental-lineage commitment.

In vitro establishment of expanded-potential stem cells from mouse pre-implantation embryos or embryonic stem cells.

Molecular and embryology studies have demonstrated that mouse pre-implantation embryo development is a process of progressive cell fate determination. At the time of implantation, three cell lineages are present in the developing blastocyst: the trophectoderm (TE), the epiblast (Epi) and the primitive endoderm (PrE). From these early embryo cells, trophoblast stem (TS) cells, embryonic stem (ES) cells and extra-embryonic endoderm stem (XEN) cells can be derived. Recently, we derived stem cells with blastomere-like features from mouse cleavage-stage embryos, which we named expanded-potential stem cells (EPSCs). Here, we provide detailed protocols that describe how to establish EPSCs from single eight-cell-stage blastomeres or whole eight-cell pre-implantation mouse embryos, or by conversion of mouse ES cells or induced pluripotent stem (iPS) cells reprogrammed from fibroblasts. It takes 2-3 weeks to derive EPSCs from each cell source. The EPSCs derived from these protocols can differentiate into all embryonic and extra-embryonic lineages when implanted into chimeras. Furthermore, bona fide TS and XEN cell lines can be derived from EPSCs in vitro.

Establishment of mouse expanded potential stem cells.

Mouse embryonic stem cells derived from the epiblast contribute to the somatic lineages and the germline but are excluded from the extra-embryonic tissues that are derived from the trophectoderm and the primitive endoderm upon reintroduction to the blastocyst. Here we report that cultures of expanded potential stem cells can be established from individual eight-cell blastomeres, and by direct conversion of mouse embryonic stem cells and induced pluripotent stem cells. Remarkably, a single expanded potential stem cell can contribute both to the embryo proper and to the trophectoderm lineages in a chimaera assay. Bona fide trophoblast stem cell lines and extra-embryonic endoderm stem cells can be directly derived from expanded potential stem cells in vitro. Molecular analyses of the epigenome and single-cell transcriptome reveal enrichment for blastomere-specific signature and a dynamic DNA methylome in expanded potential stem cells. The generation of mouse expanded potential stem cells highlights the feasibility of establishing expanded potential stem cells for other mammalian species.

A review of the role of stem cells in the development and treatment of glioma.

The neurosurgical management of patients with intrinsic glial cancers is one of the most rapidly evolving areas of practice. This has been fuelled by advances in surgical technique not only in cytoreduction but also in drug delivery. Further innovation will depend on a deeper understanding of the biology of the disease and an appreciation of the limitations of current knowledge. Here we review the controversial topic of cancer stem cells applied to glioma to provide neurosurgeons with a working overview. It is now recognised that the adult human brain contains regionally specified cell populations capable of self-renewal that may contribute to tumour growth and maintenance following accumulated mutational change. Tumour cells adapted to maintain growth demonstrate some stem-like characteristics and as such constitute a legitimate therapeutic target. Cellular reprogramming technologies raise the potential of developing stem cells as novel surgical tools to target disease and possibly ameliorate some of the consequences of treatment. Achieving these goals remains a significant challenge to neurosurgical oncologists, not least in challenging how we think about treating brain cancer. This review will briefly examine our understanding of adult stem cells within the brain, the evidence that they contribute to the development of brain tumours as tumour-initiating cells, and the potential implications for therapy. It will also look at the role stem cells may play in the future management of glioma.

Protein digestibility-corrected amino acid scores (PDCAAS) for soy protein isolates and concentrate: criteria for evaluation.

Protein quality, as determined by the PDCAAS method, is a measure of a protein's ability to provide adequate levels of essential amino acids for human needs. PDCAAS is calculated using an amino acid profile and true digestibility of a food protein. Soy protein is recognized as a high quality plant protein, but published PDCAAS values may vary based on the soy protein ingredient as well as the reproducibility and accuracy of the testing methods. Comparison of PDCAAS values for four differently processed soy ingredients, including three isolated soy proteins (ISP) and one soy protein concentrate (SPC), was made using two different laboratories with evaluation of the impact of the reproducibility and accuracy of amino acid profiles. PDCAAS calculations, using amino acid values from one laboratory, yielded a truncated PDCAAS of 1.00 for all four ingredients, while a second laboratory provided statistically significantly lower scores (0.95-1.00). We conclude that analytical method error can be a significant contributor to PDCAAS differences and can be mitigated by the application of amino acid nitrogen recovery correction factors.

Bacterial endophytes: recent developments and applications.

Endophytic bacteria have been found in virtually every plant studied, where they colonize the internal tissues of their host plant and can form a range of different relationships including symbiotic, mutualistic, commensalistic and trophobiotic. Most endophytes appear to originate from the rhizosphere or phyllosphere; however, some may be transmitted through the seed. Endophytic bacteria can promote plant growth and yield and can act as biocontrol agents. Endophytes can also be beneficial to their host by producing a range of natural products that could be harnessed for potential use in medicine, agriculture or industry. In addition, it has been shown that they have the potential to remove soil contaminants by enhancing phytoremediation and may play a role in soil fertility through phosphate solubilization and nitrogen fixation. There is increasing interest in developing the potential biotechnological applications of endophytes for improving phytoremediation and the sustainable production of nonfood crops for biomass and biofuel production.

An acquired efflux system is responsible for copper resistance in Xanthomonas strain IG-8 isolated from China.

The genus Xanthomonas contains plant pathogens exhibiting innate resistance to a range of antimicrobial agents. In other genera, multidrug resistance is mediated by a synergy between a low-permeability outer membrane and expression of a number of multidrug efflux systems. This report describes the isolation of a novel gene cluster xmeRSA from Xanthomonas strain IG-8 that mediates copper chloride resistance. Subsequent analysis of these genes showed that they were responsible for the high level of multiple resistance in this strain and were homologues of the sme system of Stenotrophomonas maltophilia. Knock-out mutants of this gene cluster indicate that these genes are required for the copper resistance phenotype of strain IG-8. Expression analysis using lacZ fusions indicates that the genes are regulated by copper and other antimicrobials. Bioinformatic analysis suggests that these genes were acquired by horizontal gene transfer.

Porcine endogenous retrovirus transmission characteristics of galactose alpha1-3 galactose-deficient pig cells.

Galactose alpha1-3 galactose (Gal) trisaccharides are present on the surface of wild-type pig cells, as well as on viruses particles produced from such cells. The recognition of Gal sugars by natural anti-Gal antibodies (NAb) in human and Old World primate serum can cause the lysis of the particles via complement-dependent mechanisms and has therefore been proposed as an important antiviral mechanism. Recently, pigs have been generated that possess disrupted galactosyl-transferase (GGTA1) genes. The cells of these pigs do not express Gal sugars on their surface, i.e., are Gal null. Concerns have been raised that the risk of virus transmission from such pigs may be increased due to the absence of the Gal sugars. We investigated the sensitivity of porcine endogenous retrovirus (PERV) produced from Gal-null and Gal-positive pig cells to inactivation by purified NAb and human serum. PERV produced in Gal-null pig cells was resistant to inactivation by either NAb or human serum. In contrast, although Gal-positive PERV particles were sensitive to inactivation by NAb and human serum, they required markedly higher concentrations of NAb for inactivation compared to the Gal-positive cells from which they were produced. Complete inactivation of Gal-positive PERV particles was not achievable despite the use of high levels of NAb, indicating that NAb-mediated inactivation of cell-free PERV particles is an inefficient process.

Production of alpha-1,3-galactosyltransferase null pigs by means of nuclear transfer with fibroblasts bearing loss of heterozygosity mutations.

Hyperacute rejection of porcine organs by old world primate recipients is mediated through preformed antibodies against galactosyl-alpha-1,3-galactose (Galalpha-1,3-Gal) epitopes expressed on the pig cell surface. Previously, we generated inbred miniature swine with a null allele of the alpha-1,3-galactosyltransferase locus (GGTA1) by nuclear transfer (NT) with gene-targeted fibroblasts. To expedite the generation of GGTA1 null pigs, we selected spontaneous null mutant cells from fibroblast cultures of heterozygous animals for use in another round of NT. An unexpectedly high rate of spontaneous loss of GGTA1 function was observed, with the vast majority of null cells resulting from loss of the WT allele. Healthy piglets, hemizygous and homozygous for the gene-targeted allele, were produced by NT by using fibroblasts that had undergone deletional and crossover/gene conversion events, respectively. Aside from loss of Galalpha-1,3-Gal epitopes, there were no obvious phenotypic differences between these null piglets and WT piglets from the same inbred lines. In fact, congenital abnormalities observed in the heterozygous NT animals did not reappear in the serially produced null animals.