2,914 research outputs found
Expression of an anti-CD4 single-chain antibody fragment from the donor cornea can prolong corneal allograft survival in inbred rats
To investigate whether expression of an anti-CD4 antibody fragment (scFv) by a lentivector-transduced donor cornea can prolong rat corneal allograft survival.
Methods Inbred Fischer 344 rats received penetrating corneal allografts from Wistar-Furth donors after a 3 h transduction of the donor cornea with a lentivector carrying anti-CD4scFv cDNA (Lv-CD4scFv), a lentivector carrying the reporter gene-enhanced yellow fluorescence protein (LV-eYFP), or an adenoviral vector carrying anti-CD4 scFv cDNA (Ad-CD4scFv). Unmodified controls were also performed. Graft survival was assessed by corneal clarity, and rejection was confirmed histologically.
Results In organ-cultured corneas, expression of anti-CD4 scFv was detected at 2 days post-transduction with the adenoviral vector, compared with 5 days post-transduction with the lentivector, and was 10-fold higher than the former. More inflammation was observed in Ad-CD4scFv-modified allografts than in Lv-CD4scFv-modified grafts at 15 days postsurgery (p=0.01). The median time to rejection for unmodified, LV-eYFP and Ad-CD4scFv grafts was day 17, compared with day 22 for Lv-CD4scFv grafts (p≤0.018).
Conclusion Donor corneas transduced with a lentiviral vector carrying anti-CD4scFv cDNA showed a modest but significant prolongation in graft survival compared with unmodified, Lv-eYFP and Ad-CD4scFv grafts. However, rejection still occurred in all Lv-CD4scFv grafts, indicating that sensitisation may have been delayed but was not prevented.Australian National Health & Medical Research Council and the Ophthalmic Research Institute of Australia
Characterization of a heat resistant beta-glucosidase as a new reporter in cells and mice.
BACKGROUND: Reporter genes are widely used in biology and only a limited number are available. We present a new reporter gene for the localization of mammalian cells and transgenic tissues based on detection of the bglA (SYNbglA) gene of Caldocellum saccharolyticum that encodes a thermophilic beta-glucosidase. RESULTS: SYNbglA was generated by introducing codon substitutions to remove CpG motifs as these are associated with gene silencing in mammalian cells. SYNbglA expression can be localized in situ or detected quantitatively in colorimetric assays and can be co-localized with E. coli beta-galactosidase. Further, we have generated a Cre-reporter mouse in which SYNbglA is expressed following recombination to demonstrate the general utility of SYNbglA for in vivo analyses. SYNbglA can be detected in tissue wholemounts and in frozen and wax embedded sections. CONCLUSIONS: SYNbglA will have general applicability to developmental and molecular studies in vitro and in vivo.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Understanding misimplementation in U.S. state health departments: An agent-based model
INTRODUCTION: The research goal of this study is to explore why misimplementation occurs in public health agencies and how it can be reduced. Misimplementation is ending effective activities prematurely or continuing ineffective ones, which contributes to wasted resources and suboptimal health outcomes.
METHODS: The study team created an agent-based model that represents how information flow, filtered through organizational structure, capacity, culture, and leadership priorities, shapes continuation decisions. This agent-based model used survey data and interviews with state health department personnel across the U.S. between 2014 and 2020; model design and analyses were conducted with substantial input from stakeholders between 2019 and 2021. The model was used experimentally to identify potential approaches for reducing misimplementation.
RESULTS: Simulations showed that increasing either organizational evidence-based decision-making capacity or information sharing could reduce misimplementation. Shifting leadership priorities to emphasize effectiveness resulted in the largest reduction, whereas organizational restructuring did not reduce misimplementation.
CONCLUSIONS: The model identifies for the first time a specific set of factors and dynamic pathways most likely driving misimplementation and suggests a number of actionable strategies for reducing it. Priorities for training the public health workforce include evidence-based decision making and effective communication. Organizations will also benefit from an intentional shift in leadership decision-making processes. On the basis of this initial, successful application of agent-based model to misimplementation, this work provides a framework for further analyses
Agricultural origins on the Anatolian plateau
This paper explores the explanations for, and consequences of, the early appearance of food production outside the Fertile Crescent of Southwest Asia, where it originated in the 10th/9th millennia cal BC. We present evidence that cultivation appeared in Central Anatolia through adoption by indigenous foragers in the mid ninth millennium cal BC, but also demonstrate that uptake was not uniform, and that some communities chose to actively disregard cultivation. Adoption of cultivation was accompanied by experimentation with sheep/goat herding in a system of low-level food production that was integrated into foraging practices rather than used to replace them. Furthermore, rather than being a short-lived transitional state, low-level food production formed part of a subsistence strategy that lasted for several centuries, although its adoption had significant long-term social consequences for the adopting community at Boncuklu. Material continuities suggest that Boncuklu’s community was ancestral to that seen at the much larger settlement of Çatalhöyük East from 7100 cal BC, by which time a modest involvement with food production had been transformed into a major commitment to mixed farming, allowing the sustenance of a very large sedentary community. This evidence from Central Anatolia illustrates that polarized positions explaining the early spread of farming, opposing indigenous adoption to farmer colonization, are unsuited to understanding local sequences of subsistence and related social change. We go beyond identifying the mechanisms for the spread of farming by investigating the shorter- and longer-term implications of rejecting or adopting farming practices.</p
Peer support for people living with hepatitis B virus—A foundation for treatment expansion
Chronic hepatitis B infection (CHB) affects 300 million people worldwide and is being targeted by the United Nations 2030 Sustainable Development Goals (SDGs) and the World Health Organisation (WHO), working towards elimination of hepatitis B virus (HBV) as a public health threat. In this piece, we explore the evidence and potential impact of peer support to enhance and promote interventions for people living with CHB. Peer support workers (PSWs) are those with lived experience of an infection, condition or situation who work to provide support for others, aiming to improve education, prevention, treatment and other clinical interventions and to reduce the physical, psychological and social impacts of disease. Peer support has been shown to be a valuable tool for improving health outcomes for people living with human immunodeficiency virus (HIV) and hepatitis C virus (HCV), but to date has not been widely available for communities affected by HBV. HBV disproportionately affects vulnerable and marginalised populations, who could benefit from PSWs to help them navigate complicated systems and provide advocacy, tackle stigma, improve education and representation, and optimise access to treatment and continuity of care. The scale up of peer support must provide structured and supportive career pathways for PSWs, account for social and cultural needs of different communities, adapt to differing healthcare systems and provide flexibility in approaches to care. Investment in peer support for people living with CHB could increase diagnosis, improve retention in care, and support design and roll out of interventions that can contribute to global elimination goals
Performance of automated scoring of ER, PR, HER2, CK5/6 and EGFR in breast cancer tissue microarrays in the Breast Cancer Association Consortium
Breast cancer risk factors and clinical outcomes vary by tumour marker expression. However, individual studies often lack the power required to assess these relationships, and large-scale analyses are limited by the need for high throughput, standardized scoring methods. To address these limitations, we assessed whether automated image analysis of immunohistochemically stained tissue microarrays can permit rapid, standardized scoring of tumour markers from multiple studies. Tissue microarray sections prepared in nine studies containing 20 263 cores from 8267 breast cancers stained for two nuclear (oestrogen receptor, progesterone receptor), two membranous (human epidermal growth factor receptor 2 and epidermal growth factor receptor) and one cytoplasmic (cytokeratin 5/6) marker were scanned as digital images. Automated algorithms were used to score markers in tumour cells using the Ariol system. We compared automated scores against visual reads, and their associations with breast cancer survival. Approximately 65–70% of tissue microarray cores were satisfactory for scoring. Among satisfactory cores, agreement between dichotomous automated and visual scores was highest for oestrogen receptor (Kappa = 0.76), followed by human epidermal growth factor receptor 2 (Kappa = 0.69) and progesterone receptor (Kappa = 0.67). Automated quantitative scores for these markers were associated with hazard ratios for breast cancer mortality in a dose-response manner. Considering visual scores of epidermal growth factor receptor or cytokeratin 5/6 as the reference, automated scoring achieved excellent negative predictive value (96–98%), but yielded many false positives (positive predictive value = 30–32%). For all markers, we observed substantial heterogeneity in automated scoring performance across tissue microarrays. Automated analysis is a potentially useful tool for large-scale, quantitative scoring of immunohistochemically stained tissue microarrays available in consortia. However, continued optimization, rigorous marker-specific quality control measures and standardization of tissue microarray designs, staining and scoring protocols is needed to enhance results.Peer reviewe
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Association of Genetic Variants With Primary Open-Angle Glaucoma Among Individuals With African Ancestry.
Importance:Primary open-angle glaucoma presents with increased prevalence and a higher degree of clinical severity in populations of African ancestry compared with European or Asian ancestry. Despite this, individuals of African ancestry remain understudied in genomic research for blinding disorders. Objectives:To perform a genome-wide association study (GWAS) of African ancestry populations and evaluate potential mechanisms of pathogenesis for loci associated with primary open-angle glaucoma. Design, Settings, and Participants:A 2-stage GWAS with a discovery data set of 2320 individuals with primary open-angle glaucoma and 2121 control individuals without primary open-angle glaucoma. The validation stage included an additional 6937 affected individuals and 14 917 unaffected individuals using multicenter clinic- and population-based participant recruitment approaches. Study participants were recruited from Ghana, Nigeria, South Africa, the United States, Tanzania, Britain, Cameroon, Saudi Arabia, Brazil, the Democratic Republic of the Congo, Morocco, Peru, and Mali from 2003 to 2018. Individuals with primary open-angle glaucoma had open iridocorneal angles and displayed glaucomatous optic neuropathy with visual field defects. Elevated intraocular pressure was not included in the case definition. Control individuals had no elevated intraocular pressure and no signs of glaucoma. Exposures:Genetic variants associated with primary open-angle glaucoma. Main Outcomes and Measures:Presence of primary open-angle glaucoma. Genome-wide significance was defined as P < 5 × 10-8 in the discovery stage and in the meta-analysis of combined discovery and validation data. Results:A total of 2320 individuals with primary open-angle glaucoma (mean [interquartile range] age, 64.6 [56-74] years; 1055 [45.5%] women) and 2121 individuals without primary open-angle glaucoma (mean [interquartile range] age, 63.4 [55-71] years; 1025 [48.3%] women) were included in the discovery GWAS. The GWAS discovery meta-analysis demonstrated association of variants at amyloid-β A4 precursor protein-binding family B member 2 (APBB2; chromosome 4, rs59892895T>C) with primary open-angle glaucoma (odds ratio [OR], 1.32 [95% CI, 1.20-1.46]; P = 2 × 10-8). The association was validated in an analysis of an additional 6937 affected individuals and 14 917 unaffected individuals (OR, 1.15 [95% CI, 1.09-1.21]; P < .001). Each copy of the rs59892895*C risk allele was associated with increased risk of primary open-angle glaucoma when all data were included in a meta-analysis (OR, 1.19 [95% CI, 1.14-1.25]; P = 4 × 10-13). The rs59892895*C risk allele was present at appreciable frequency only in African ancestry populations. In contrast, the rs59892895*C risk allele had a frequency of less than 0.1% in individuals of European or Asian ancestry. Conclusions and Relevance:In this genome-wide association study, variants at the APBB2 locus demonstrated differential association with primary open-angle glaucoma by ancestry. If validated in additional populations this finding may have implications for risk assessment and therapeutic strategies
NGTS-21b: An Inflated Super-Jupiter Orbiting a Metal-poor K dwarf
We report the discovery of NGTS-21b, a massive hot Jupiter orbiting a
low-mass star as part of the Next Generation Transit Survey (NGTS). The planet
has a mass and radius of M, and
R, and an orbital period of 1.543 days. The host is a K3V (, K) metal-poor (, dex) dwarf
star with a mass and radius of , M,and , R. Its age and rotation period of , Gyr
and , d respectively, are in accordance with the observed
moderately low stellar activity level. When comparing NGTS-21b with currently
known transiting hot Jupiters with similar equilibrium temperatures, it is
found to have one of the largest measured radii despite its large mass.
Inflation-free planetary structure models suggest the planet's atmosphere is
inflated by , while inflationary models predict a radius consistent
with observations, thus pointing to stellar irradiation as the probable origin
of NGTS-21b's radius inflation. Additionally, NGTS-21b's bulk density (, g/cm) is also amongst the largest within the population of
metal-poor giant hosts ([Fe/H] < 0.0), helping to reveal a falling upper
boundary in metallicity-planet density parameter space that is in concordance
with core accretion formation models. The discovery of rare planetary systems
such as NGTS-21 greatly contributes towards better constraints being placed on
the formation and evolution mechanisms of massive planets orbiting low-mass
stars.Comment: 12 pages, 13 figures, accepted for publication in MNRA
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