1,404 research outputs found

    A plesiosaur containing an ichthyosaur embryo as stomach contents from the Sundance Formation of the Bighorn Basin, Wyoming

    Get PDF
    Herein we report the discovery of an ichthyosaur embryo from the Upper Member of the Sundance Formation (Oxfordian) of the Bighorn Basin, Wyoming. The specimen is the first known ichthyosaur embryo from the Upper Jurassic, and is the first Jurassic ichthyosaur embryo from North America. The embryo was discovered in close association with the abdomen of an articulated partial plesiosaur skeleton, and several lines of evidence support the interpretation of the embryo as plesiosaur stomach contents. The small size and extremely poor ossification of the embryo indicate that the animal was probably not a neonate. Although the taxonomic affinities of the fossil are unknown, the large ichthyosaurian (sensu stricto) Opthalmosaurus natans is the only known ichthyosaur from the Sundance Formation, and the embryo may belong to that taxon

    Association of maternal circulating 25(OH)D and calcium with birth weight: A mendelian randomisation analysis

    Get PDF
    Systematic reviews of randomised controlled trials (RCTs) have suggested that maternal vitamin D (25[OH]D) and calcium supplementation increase birth weight. However, limitations of many trials were highlighted in the reviews. Our aim was to combine genetic and RCT data to estimate causal effects of these two maternal traits on offspring birth weight

    Chemokine (C-C Motif) Receptor 2 Mediates Dendritic Cell Recruitment to the Human Colon but Is Not Responsible for Differences Observed in Dendritic Cell Subsets, Phenotype, and Function Between the Proximal and Distal Colon.

    Get PDF
    BACKGROUND & AIMS: Most knowledge about gastrointestinal (GI)-tract dendritic cells (DC) relies on murine studies where CD103+ DC specialize in generating immune tolerance with the functionality of CD11b+/- subsets being unclear. Information about human GI-DC is scarce, especially regarding regional specifications. Here, we characterized human DC properties throughout the human colon. METHODS: Paired proximal (right/ascending) and distal (left/descending) human colonic biopsies from 95 healthy subjects were taken; DC were assessed by flow cytometry and microbiota composition assessed by 16S rRNA gene sequencing. RESULTS: Colonic DC identified were myeloid (mDC, CD11c+CD123-) and further divided based on CD103 and SIRPα (human analog of murine CD11b) expression. CD103-SIRPα+ DC were the major population and with CD103+SIRPα+ DC were CD1c+ILT3+CCR2+ (although CCR2 was not expressed on all CD103+SIRPα+ DC). CD103+SIRPα- DC constituted a minor subset that were CD141+ILT3-CCR2-. Proximal colon samples had higher total DC counts and fewer CD103+SIRPα+ cells. Proximal colon DC were more mature than distal DC with higher stimulatory capacity for CD4+CD45RA+ T-cells. However, DC and DC-invoked T-cell expression of mucosal homing markers (β7, CCR9) was lower for proximal DC. CCR2 was expressed on circulating CD1c+, but not CD141+ mDC, and mediated DC recruitment by colonic culture supernatants in transwell assays. Proximal colon DC produced higher levels of cytokines. Mucosal microbiota profiling showed a lower microbiota load in the proximal colon, but with no differences in microbiota composition between compartments. CONCLUSIONS: Proximal colonic DC subsets differ from those in distal colon and are more mature. Targeted immunotherapy using DC in T-cell mediated GI tract inflammation may therefore need to reflect this immune compartmentalization

    Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

    Get PDF
    Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition

    The endoplasmic reticulum stress marker CHOP predicts survival in malignant mesothelioma.

    Get PDF
    BACKGROUND: Mesothelioma is an incurable cancer originating from the mesothelial cells that line the pleural, peritoneal and pericardial cavities. These cells synthesise large quantities of surface glycoproteins, rendering them dependent upon efficient endoplasmic reticulum (ER) function. When faced with elevated levels of secretory protein load, cells are said to experience ER stress, which has been implicated in the pathogenesis of many human diseases including cancer. METHOD: We set out to measure markers of ER stress in malignant mesothelioma and to determine whether ER stress signalling correlates with clinical parameters. RESULTS: We observed that expression of the ER stress-responsive transcription factor C/EBP homologous protein (CHOP) correlated with patient survival and remained an independent prognostic variable in pairwise comparisons with all clinical variables tested. The most parsimonious multivariate model in our study comprised only performance status and CHOP staining. In contrast, expression of the ER stress-responsive phosphatase growth arrest and DNA damage 34 (GADD34) correlated with the degree of mesothelial differentiation, being lost progressively in biphasic and sarcomatoid mesotheliomas. CONCLUSION: Our findings suggest that staining for CHOP provides prognostic information that may be useful in the stratification of patients with mesothelioma. Staining for GADD34 may prove useful in classification of mesothelioma histopathology
    corecore