Differential Effects of Sorafenib on Liver Versus Tumor Fibrosis Mediated by Stromal-Derived Factor 1 alpha/C-X-C Receptor Type 4 Axis and Myeloid Differentiation Antigen-Positive Myeloid Cell Infiltration in Mice

Sorafenib—a broad kinase inhibitor—is a standard therapy for advanced hepatocellular carcinoma (HCC) and has been shown to exert antifibrotic effects in liver cirrhosis, a precursor of HCC. However, the effects of sorafenib on tumor desmoplasia—and its consequences on treatment resistance—remain unknown. We demonstrate that sorafenib has differential effects on tumor fibrosis versus liver fibrosis in orthotopic models of HCC in mice. Sorafenib intensifies tumor hypoxia, which increases stromal-derived factor 1 alpha (SDF-1α) expression in cancer and stromal cells and, subsequently, myeloid differentiation antigen–positive (Gr-1+) myeloid cell infiltration. The SDF-1α/C-X-C receptor type 4 (CXCR4) pathway directly promotes hepatic stellate cell (HSC) differentiation and activation through the mitogen-activated protein kinase pathway. This is consistent with the association between SDF-1α expression with fibrotic septa in cirrhotic liver tissues as well as with desmoplastic regions of human HCC samples. We demonstrate that after treatment with sorafenib, SDF-1α increased the survival of HSCs and their alpha-smooth muscle actin and collagen I expression, thus increasing tumor fibrosis. Finally, we show that Gr-1+ myeloid cells mediate HSC differentiation and activation in a paracrine manner. CXCR4 inhibition, using AMD3100 in combination with sorafenib treatment, prevents the increase in tumor fibrosis—despite persistently elevated hypoxia—in part by reducing Gr-1+ myeloid cell infiltration and inhibits HCC growth. Similarly, antibody blockade of Gr-1 reduces tumor fibrosis and inhibits HCC growth when combined with sorafenib treatment. Conclusion: Blocking SDF-1α/CXCR4 or Gr-1+ myeloid cell infiltration may reduce hypoxia-mediated HCC desmoplasia and increase the efficacy of sorafenib treatment. (Hepatology 2014;59:1435-1447

Neuroanatomical heterogeneity and homogeneity in individuals at clinical high risk for psychosis

Individuals at Clinical High Risk for Psychosis (CHR-P) demonstrate heterogeneity in clinical profiles and outcome features. However, the extent of neuroanatomical heterogeneity in the CHR-P state is largely undetermined. We aimed to quantify the neuroanatomical heterogeneity in structural magnetic resonance imaging measures of cortical surface area (SA), cortical thickness (CT), subcortical volume (SV), and intracranial volume (ICV) in CHR-P individuals compared with healthy controls (HC), and in relation to subsequent transition to a first episode of psychosis. The ENIGMA CHR-P consortium applied a harmonised analysis to neuroimaging data across 29 international sites, including 1579 CHR-P individuals and 1243 HC, offering the largest pooled CHR-P neuroimaging dataset to date. Regional heterogeneity was indexed with the Variability Ratio (VR) and Coefficient of Variation (CV) ratio applied at the group level. Personalised estimates of heterogeneity of SA, CT and SV brain profiles were indexed with the novel Person-Based Similarity Index (PBSI), with two complementary applications. First, to assess the extent of within-diagnosis similarity or divergence of neuroanatomical profiles between individuals. Second, using a normative modelling approach, to assess the ‘normativeness’ of neuroanatomical profiles in individuals at CHR-P. CHR-P individuals demonstrated no greater regional heterogeneity after applying FDR corrections. However, PBSI scores indicated significantly greater neuroanatomical divergence in global SA, CT and SV profiles in CHR-P individuals compared with HC. Normative PBSI analysis identified 11 CHR-P individuals (0.70%) with marked deviation (>1.5 SD) in SA, 118 (7.47%) in CT and 161 (10.20%) in SV. Psychosis transition was not significantly associated with any measure of heterogeneity. Overall, our examination of neuroanatomical heterogeneity within the CHR-P state indicated greater divergence in neuroanatomical profiles at an individual level, irrespective of psychosis conversion. Further large-scale investigations are required of those who demonstrate marked deviation.publishedVersio

Naturalistic Observation of Children in Cars: An International Partnership

It is well known that in the rear seat of cars, small children squirm, slide, slump, sleep, play and interact with their fellow passengers. Our previous findings from a pilot study show that children rarely remain in an optimal position for the efficient functioning of their restraint systems throughout the duration of their journey. Such behaviours may not only affect restraint effectiveness but may also have a negative influence on driver performance and distraction. Moreover, quantification of children’s position and out-of-position (OOP) status (i.e., their actual position relative to the ideal position for which the technology was designed) has important implications for design of test programs using anthropomorphic test devices (ATD) intended to mimic the human occupant. For example, understanding true pre-crash positions may lead to different design specifications of rear seat restraint systems and energy management features of the vehicle interior compared with the kinds of solutions that might arise from evaluations with an in-position ATD. This paper builds on our preliminary research findings and describes the design of the first international large-scale study of children in cars which uses innovative methods to observe and quantify the positions of child occupants in cars and identify the injury effects of OOP status and its impact on driver distraction. The study will facilitate a paradigm-shifting advance in child occupant protection – from the concept of safety technology designed to protect an ideally positioned occupant to the concept of dynamic restraint systems that maintain optimal restraint over a range of expected child positions/movements in a vehicle. Outcomes of the research will directly inform the design of future restraints for children, the development of appropriate crash test procedures that account for natural positions of child occupants, and the development of community awareness messages to improve the safety of children

Naturalistic Observation of Children in Cars: An International Partnership

It is well known that in the rear seat of cars, small children squirm, slide, slump, sleep, play and interact with their fellow passengers. Our previous findings from a pilot study show that children rarely remain in an optimal position for the efficient functioning of their restraint systems throughout the duration of their journey. Such behaviours may not only affect restraint effectiveness but may also have a negative influence on driver performance and distraction. Moreover, quantification of children’s position and out-of-position (OOP) status (i.e., their actual position relative to the ideal position for which the technology was designed) has important implications for design of test programs using anthropomorphic test devices (ATD) intended to mimic the human occupant. For example, understanding true pre-crash positions may lead to different design specifications of rear seat restraint systems and energy management features of the vehicle interior compared with the kinds of solutions that might arise from evaluations with an in-position ATD. This paper builds on our preliminary research findings and describes the design of the first international large-scale study of children in cars which uses innovative methods to observe and quantify the positions of child occupants in cars and identify the injury effects of OOP status and its impact on driver distraction. The study will facilitate a paradigm-shifting advance in child occupant protection – from the concept of safety technology designed to protect an ideally positioned occupant to the concept of dynamic restraint systems that maintain optimal restraint over a range of expected child positions/movements in a vehicle. Outcomes of the research will directly inform the design of future restraints for children, the development of appropriate crash test procedures that account for natural positions of child occupants, and the development of community awareness messages to improve the safety of children

Identification of the mycobacterial carbohydrate structure that binds the C-type lectins DC-SIGN, L-SIGN and SIGNR1

Mycobacterium tuberculosis represents a worldwide health risk and although macrophages are primarily infected, dendritic cells (DC) are important in inducing cellular immune responses against M. tuberculosis. Recent studies have demonstrated that M. tuberculosis targets the DC-specific C-type lectin DC-SIGN to inhibit the immuno-stimulatory function of DC through the interaction of the mycobacterial mannosylated lipoarabinomannan (ManLAM) to DC-SIGN, which prevents DC maturation and induces the immuno-suppressive cytokine IL-10. This may contribute to survival and persistence of M. tuberculosis. Here, we have identified the specific pathogen-derived carbohydrate structure on ManLAM that is recognized by DC-SIGN. We have synthesized the mannose-cap oligosaccharides man-ara, (man)2-ara and (man)3-ara, and demonstrate that these neoglycoconjugates are specifically bound by DC-SIGN. Moreover, we demonstrate that the human and murine DC-SIGN homologue L-SIGN and SIGNR1, respectively, also interact with mycobacteria through ManLAM. Both homologues have the highest affinity for the (man)3-ara structure, similar to DC-SIGN. This study provides information about the specific carbohydrate structures on pathogens that are recognized by DC-SIGN, and may provide strategies to develop vaccines against these pathogens. Moreover, the identification of SIGNR1 as a receptor for ManLAM will enable in vivo studies to investigate the role of DC-SIGN in M. tuberculosis pathogenesi

Association of Structural Magnetic Resonance Imaging Measures With Psychosis Onset in Individuals at Clinical High Risk for Developing Psychosis: An ENIGMA Working Group Mega-analysis

The ENIGMA clinical high risk (CHR) for psychosis initiative, the largest pooled neuroimaging sample of individuals at CHR to date, aims to discover robust neurobiological markers of psychosis risk