662 research outputs found

    Birthweight and risk markers for type 2 diabetes and cardiovascular disease in childhood: the Child Heart and Health Study in England (CHASE).

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    AIMS/HYPOTHESIS: Lower birthweight (a marker of fetal undernutrition) is associated with higher risks of type 2 diabetes and cardiovascular disease (CVD) and could explain ethnic differences in these diseases. We examined associations between birthweight and risk markers for diabetes and CVD in UK-resident white European, South Asian and black African-Caribbean children. METHODS: In a cross-sectional study of risk markers for diabetes and CVD in 9- to 10-year-old children of different ethnic origins, birthweight was obtained from health records and/or parental recall. Associations between birthweight and risk markers were estimated using multilevel linear regression to account for clustering in children from the same school. RESULTS: Key data were available for 3,744 (66%) singleton study participants. In analyses adjusted for age, sex and ethnicity, birthweight was inversely associated with serum urate and positively associated with systolic BP. After additional height adjustment, lower birthweight (per 100 g) was associated with higher serum urate (0.52%; 95% CI 0.38, 0.66), fasting serum insulin (0.41%; 95% CI 0.08, 0.74), HbA1c (0.04%; 95% CI 0.00, 0.08), plasma glucose (0.06%; 95% CI 0.02, 0.10) and serum triacylglycerol (0.30%; 95% CI 0.09, 0.51) but not with BP or blood cholesterol. Birthweight was lower among children of South Asian (231 g lower; 95% CI 183, 280) and black African-Caribbean origin (81 g lower; 95% CI 30, 132). However, adjustment for birthweight had no effect on ethnic differences in risk markers. CONCLUSIONS/INTERPRETATION: Birthweight was inversely associated with urate and with insulin and glycaemia after adjustment for current height. Lower birthweight does not appear to explain emerging ethnic difference in risk markers for diabetes

    An evaluation of sorter induced cell stress (SICS) on peripheral blood mononuclear cells (PBMCs) after different sort conditions - are your sorted cells getting SICS?

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    Flow cytometry and fluorescence-activated cell sorting have become invaluable tools to analyze and isolate specific cell populations in a wide range of biomedical research and clinical applications. In countless approaches worldwide, scientists are using single cell analyses to better understand the significance and variation within different cellular populations, and fluorescence-activated cell sorting has become a major technique for cell isolation in both basic and clinical research. However, majority of available cell sorters are pressurized, droplet-based systems, which apply significant environmental pressure and shear stress to cells during sorting. Recently, the flow cytometry community has become increasingly aware about the potential negative effects this could have on sorted cells and the term "sorter induced cell stress" (SICS) has been proposed. However, up to date only a limited number of studies have investigated the effects of cell sorting on cell viability and function. Therefore, solid data on the effects of sheath pressure and nozzle size on survival and function of sorted cells are surprisingly rare. With this in mind, we sorted "CD4 " T-cells and "live" cells from human peripheral blood mononuclear cells (PBMCs) at different sort conditions and analyzed their quality before and after sorting in a series of assays. Here we present our findings in reference to cell viability and cell proliferation following sorting on different instruments (BD FACSAria III SORP and BD FACSJazz), utilizing different nozzle sizes (70 to 100 μm) and sheath pressure settings (20 to 70 psi). The results show no significant differences in cell viability and proliferation after the different tested sort conditions, but rather differences between individual experiments. These findings are evaluated and their potential significance in cell sorting experiments is discussed. [Abstract copyright: Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.

    Robust molecular subgrouping and reference-free aneuploidy detection in medulloblastoma using low-depth whole genome bisulfite sequencing

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    \ua9 The Author(s) 2025.Medulloblastoma comprises four principal molecular disease groups and their component subgroups, each with distinct molecular and clinical features. Group assignment is currently achieved diagnostically using Illumina DNA methylation microarray. Whole-genome sequencing (WGS) capacity is rapidly expanding in the clinical setting and the development of platform-independent, sequence-based assays of molecular group offers significant potential. Specifically, whole-genome bisulfite sequencing (WGBS) enables assessment of genome-wide methylation status at single-base resolution, however its routine application has been limited by high DNA input requirements, cost, and a lack of pipelines tailored to more rapidly-acquired and cost-effective low-depth (< 10x) sequencing data. We utilised WGBS data for 69 medulloblastomas, comprising 35 in-house low-depth (~ 10x) and 34 publicly available high-depth (~ 30x) samples, alongside cerebellar controls (n = 8), all with matched DNA methylation microarray data. We assessed quality (QC) and imputation approaches using low-pass WGBS data, assessed inter-platform correlation and identified molecular groups and subgroups by directly integrating matched/associated loci from WGBS sample data with the MNP classifier probeset. We further assessed and optimised reference-free aneuploidy detection using low-pass WGBS and assessed concordance with microarray-derived calls. We developed and optimised pipelines for processing, QC, and analysis of low-pass WGBS data, suitable for routine molecular subgrouping and reference-free aneuploidy assessment. We demonstrate that low-pass WGBS data can (i) be integrated into existing array-trained models with high assignment probabilities for both principal molecular groups (97% concordance) and molecular subgroups (94.2% concordance), and (ii) detect clinically relevant focal copy number changes, including SNCAIP, with greater sensitivity than microarray approaches. Low-pass WGBS performs equivalently to array-based methods at comparable cost. Finally, its ascertainment of the full methylome enables elucidation of additional biological complexity and inter-tumoural heterogeneity that has hitherto been inaccessible. These findings provide proof-of-concept for clinical adoption of low-pass WGBS, applied using standard WGS technology

    Epidemiology and interactions of Human Immunodeficiency Virus - 1 and Schistosoma mansoni in sub-Saharan Africa.

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    Human Immunodeficiency Virus-1/AIDS and Schistosoma mansoni are widespread in sub-Saharan Africa and co-infection occurs commonly. Since the early 1990s, it has been suggested that the two infections may interact and potentiate the effects of each other within co-infected human hosts. Indeed, S. mansoni infection has been suggested to be a risk factor for HIV transmission and progression in Africa. If so, it would follow that mass deworming could have beneficial effects on HIV-1 transmission dynamics. The epidemiology of HIV in African countries is changing, shifting from urban to rural areas where the prevalence of Schistosoma mansoni is high and public health services are deficient. On the other side, the consequent pathogenesis of HIV-1/S. mansoni co-infection remains unknown. Here we give an account of the epidemiology of HIV-1 and S. mansoni, discuss co-infection and possible biological causal relationships between the two infections, and the potential impact of praziquantel treatment on HIV-1 viral loads, CD4+ counts and CD4+/CD8+ ratio. Our review of the available literature indicates that there is evidence to support the hypothesis that S. mansoni infections can influence the replication of the HIV-1, cell-to-cell transmission, as well as increase HIV progression as measured by reduced CD4+ T lymphocytes counts. If so, then deworming of HIV positive individuals living in endemic areas may impact on HIV-1 viral loads and CD4+ T lymphocyte counts.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

    Pharmacokinetic-Pharmacodynamic Modeling in Pediatric Drug Development, and the Importance of Standardized Scaling of Clearance.

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    Pharmacokinetic/pharmacodynamic (PKPD) modeling is important in the design and conduct of clinical pharmacology research in children. During drug development, PKPD modeling and simulation should underpin rational trial design and facilitate extrapolation to investigate efficacy and safety. The application of PKPD modeling to optimize dosing recommendations and therapeutic drug monitoring is also increasing, and PKPD model-based dose individualization will become a core feature of personalized medicine. Following extensive progress on pediatric PK modeling, a greater emphasis now needs to be placed on PD modeling to understand age-related changes in drug effects. This paper discusses the principles of PKPD modeling in the context of pediatric drug development, summarizing how important PK parameters, such as clearance (CL), are scaled with size and age, and highlights a standardized method for CL scaling in children. One standard scaling method would facilitate comparison of PK parameters across multiple studies, thus increasing the utility of existing PK models and facilitating optimal design of new studies

    Molecular Biomechanics: The Molecular Basis of How Forces Regulate Cellular Function

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    Recent advances have led to the emergence of molecular biomechanics as an essential element of modern biology. These efforts focus on theoretical and experimental studies of the mechanics of proteins and nucleic acids, and the understanding of the molecular mechanisms of stress transmission, mechanosensing and mechanotransduction in living cells. In particular, single-molecule biomechanics studies of proteins and DNA, and mechanochemical coupling in biomolecular motors have demonstrated the critical importance of molecular mechanics as a new frontier in bioengineering and life sciences. To stimulate a more systematic study of the basic issues in molecular biomechanics, and attract a broader range of researchers to enter this emerging field, here we discuss its significance and relevance, describe the important issues to be addressed and the most critical questions to be answered, summarize both experimental and theoretical/computational challenges, and identify some short-term and long-term goals for the field. The needs to train young researchers in molecular biomechanics with a broader knowledge base, and to bridge and integrate molecular, subcellular and cellular level studies of biomechanics are articulated.National Institutes of Health (U.S.) (grant UO1HL80711-05 to GB)National Institutes of Health (U.S.) (grant R01GM076689-01)National Institutes of Health (U.S.) (grant R01AR033236-26)National Institutes of Health (U.S.) (grant R01GM087677-01A1)National Institutes of Health (U.S.) (grant R01AI44902)National Institutes of Health (U.S.) (grant R01AI38282)National Science Foundation (U.S.) (grant CMMI-0645054)National Science Foundation (U.S.) (grant CBET-0829205)National Science Foundation (U.S.) (grant CAREER-0955291

    Molecular and clinical heterogeneity within MYC-family amplified medulloblastoma is associated with survival outcomes: A multicenter cohort study

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    \ua9 The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Neuro-Oncology.Background.MYC/MYCN are the most frequent oncogene amplifications in medulloblastoma (MB) and its primary biomarkers of high-risk (HR) disease. However, while many patients’ MYC(N)-amplified tumors are treatment-refractory, some achieve long-term survival. We therefore investigated clinicobiological heterogeneity within MYC(N)-amplified MB and determined its relevance for improved disease management. Methods. We characterized the clinical and molecular correlates of MYC- (MYC-MB; n = 64) and MYCN-amplified MBs (MYCN-MB; n = 95), drawn from >1600 diagnostic cases. Results. Most MYC-MBs were molecular group 3 (46/58; 79% assessable) and aged ≥3 years at diagnosis (44/64 [69%]). We identified a “canonical” very high-risk (VHR) MYC-amplified group (n = 51/62; 82%) with dismal survival irrespective of treatment (11% 5-year progression-free survival [PFS]), defined by co-occurrence with ≥1 additional established risk factor(s) (subtotal surgical-resection [STR], metastatic disease, LCA pathology), and commonly group 3/4 subgroup 2 with a high proportion of amplified cells. The majority of remaining noncanonical MYC-MBs survived (i.e. non-group 3/group 3 without other risk features; 11/62 (18%); 61% 5-year PFS).MYCN survival was primarily related to molecular group; MYCN-amplified SHH MB, and group 3/4 MB with additional risk factors, respectively defined VHR and HR groups (VHR, 39% [35/89]; 20% 5-year PFS/HR, 33% [29/89]; 46% 5-year PFS). Twenty-two out of 35 assessable MYCN-amplified SHH tumors harbored TP53 mutations; 9/12 (75%) with data were germline.MYCN-amplified group 3/4 MB with no other risk factors (28%; 25/89) had 70% 5-year PFS. Conclusions.MYC(N)-amplified MB displays significant clinicobiological heterogeneity. Diagnostics incorporating molecular groups, subgroups, and clinical factors enable their risk assessment. VHR “canonical” MYC tumors are essentially incurable and SHH-MYCN-amplified MBs fare extremely poorly (20% survival at 5 years); both require urgent development of alternative treatment strategies. Conventional risk-adapted therapies are appropriate for more responsive groups, such as noncanonical MYC and non-SHH-MYCN MB

    A Summary of the Inaugural WHO Classification of Pediatric Tumors: Transitioning from the Optical into the Molecular Era

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    Pediatric tumors are uncommon, yet are the leading cause of cancer-related death in childhood. Tumor types, molecular characteristics, and pathogenesis are unique, often originating from a single genetic driver event. The specific diagnostic challenges of childhood tumors led to the development of the first World Health Organization (WHO) Classification of Pediatric Tumors. The classification is rooted in a multilayered approach, incorporating morphology, IHC, and molecular characteristics. The volume is organized according to organ sites and provides a single, state-of-the-art compendium of pediatric tumor types. A special emphasis was placed on “blastomas,” which variably recapitulate the morphologic maturation of organs from which they originate

    Cellular development and evolution of the mammalian cerebellum

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    \ua9 2023, The Author(s).The expansion of the neocortex, a hallmark of mammalian evolution 1,2, was accompanied by an increase in cerebellar neuron numbers 3. However, little is known about the evolution of the cellular programmes underlying the development of the cerebellum in mammals. In this study we generated single-nucleus RNA-sequencing data for around 400,000 cells to trace the development of the cerebellum from early neurogenesis to adulthood in human, mouse and the marsupial opossum. We established a consensus classification of the cellular diversity in the developing mammalian cerebellum and validated it by spatial mapping in the fetal human cerebellum. Our cross-species analyses revealed largely conserved developmental dynamics of cell-type generation, except for Purkinje cells, for which we observed an expansion of early-born subtypes in the human lineage. Global transcriptome profiles, conserved cell-state markers and gene-expression trajectories across neuronal differentiation show that cerebellar cell-type-defining programmes have been overall preserved for at least 160 million years. However, we also identified many orthologous genes that gained or lost expression in cerebellar neural cell types in one of the species or evolved new expression trajectories during neuronal differentiation, indicating widespread gene repurposing at the cell-type level. In sum, our study unveils shared and lineage-specific gene-expression programmes governing the development of cerebellar cells and expands our understanding of mammalian brain evolution
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