43 research outputs found

    Number crunching in the cancer stem cell market

    Get PDF
    Like their normal counterparts, many tumours are thought to have a hierarchical organization, albeit a disorganized one. Accordingly, the concept of cancer stem cells has emerged, and that these cells are responsible for perpetuating tumour existence. Operationally, cancer stem cells are regarded as prospectively purified cells that are the most effective at tumour initiation in an in vivo assay, usually after xenotransplantation to NOD/SCID mice. The conventional wisdom is that such tumour-initiating cells are rare based upon having to xenotransplant large numbers of human tumour cells into immunodeficient mice to propagate the tumour, but new evidence indicates that perhaps these cells are not so rare, at least in malignant melanoma, if a supportive soil is provided for the transplanted cells along with further restriction of the murine host's immune response

    Increased peri-ductal collagen micro-organization may contribute to raised mammographic density

    Get PDF
    BACKGROUND: High mammographic density is a therapeutically modifiable risk factor for breast cancer. Although mammographic density is correlated with the relative abundance of collagen-rich fibroglandular tissue, the causative mechanisms, associated structural remodelling and mechanical consequences remain poorly defined. In this study we have developed a new collaborative bedside-to-bench workflow to determine the relationship between mammographic density, collagen abundance and alignment, tissue stiffness and the expression of extracellular matrix organising proteins. METHODS: Mammographic density was assessed in 22 post-menopausal women (aged 54–66 y). A radiologist and a pathologist identified and excised regions of elevated non-cancerous X-ray density prior to laboratory characterization. Collagen abundance was determined by both Masson’s trichrome and Picrosirius red staining (which enhances collagen birefringence when viewed under polarised light). The structural specificity of these collagen visualisation methods was determined by comparing the relative birefringence and ultrastructure (visualised by atomic force microscopy) of unaligned collagen I fibrils in reconstituted gels with the highly aligned collagen fibrils in rat tail tendon. Localised collagen fibril organisation and stiffness was also evaluated in tissue sections by atomic force microscopy/spectroscopy and the abundance of key extracellular proteins was assessed using mass spectrometry. RESULTS: Mammographic density was positively correlated with the abundance of aligned periductal fibrils rather than with the abundance of amorphous collagen. Compared with matched tissue resected from the breasts of low mammographic density patients, the highly birefringent tissue in mammographically dense breasts was both significantly stiffer and characterised by large (>80 μm long) fibrillar collagen bundles. Subsequent proteomic analyses not only confirmed the absence of collagen fibrosis in high mammographic density tissue, but additionally identified the up-regulation of periostin and collagen XVI (regulators of collagen fibril structure and architecture) as potential mediators of localised mechanical stiffness. CONCLUSIONS: These preliminary data suggest that remodelling, and hence stiffening, of the existing stromal collagen microarchitecture promotes high mammographic density within the breast. In turn, this aberrant mechanical environment may trigger neoplasia-associated mechanotransduction pathways within the epithelial cell population. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13058-015-0664-2) contains supplementary material, which is available to authorized users

    Symptom-based stratification of patients with primary Sjögren's syndrome: multi-dimensional characterisation of international observational cohorts and reanalyses of randomised clinical trials

    Get PDF
    Background Heterogeneity is a major obstacle to developing effective treatments for patients with primary Sjögren's syndrome. We aimed to develop a robust method for stratification, exploiting heterogeneity in patient-reported symptoms, and to relate these differences to pathobiology and therapeutic response. Methods We did hierarchical cluster analysis using five common symptoms associated with primary Sjögren's syndrome (pain, fatigue, dryness, anxiety, and depression), followed by multinomial logistic regression to identify subgroups in the UK Primary Sjögren's Syndrome Registry (UKPSSR). We assessed clinical and biological differences between these subgroups, including transcriptional differences in peripheral blood. Patients from two independent validation cohorts in Norway and France were used to confirm patient stratification. Data from two phase 3 clinical trials were similarly stratified to assess the differences between subgroups in treatment response to hydroxychloroquine and rituximab. Findings In the UKPSSR cohort (n=608), we identified four subgroups: Low symptom burden (LSB), high symptom burden (HSB), dryness dominant with fatigue (DDF), and pain dominant with fatigue (PDF). Significant differences in peripheral blood lymphocyte counts, anti-SSA and anti-SSB antibody positivity, as well as serum IgG, κ-free light chain, β2-microglobulin, and CXCL13 concentrations were observed between these subgroups, along with differentially expressed transcriptomic modules in peripheral blood. Similar findings were observed in the independent validation cohorts (n=396). Reanalysis of trial data stratifying patients into these subgroups suggested a treatment effect with hydroxychloroquine in the HSB subgroup and with rituximab in the DDF subgroup compared with placebo. Interpretation Stratification on the basis of patient-reported symptoms of patients with primary Sjögren's syndrome revealed distinct pathobiological endotypes with distinct responses to immunomodulatory treatments. Our data have important implications for clinical management, trial design, and therapeutic development. Similar stratification approaches might be useful for patients with other chronic immune-mediated diseases. Funding UK Medical Research Council, British Sjogren's Syndrome Association, French Ministry of Health, Arthritis Research UK, Foundation for Research in Rheumatology

    Medullary Carcinoma of the Thyroid with Bone Metastasis

    No full text
    A woman with medullary carcinoma of the thyroid and a past history of breast cancer was found to have metastatic bone lesions. It was initially assumed that this was due to recurrent breast carcinoma, but bone biopsy revealed medullary carcinoma of thyroid origin. Although clinical bone metastasis is a rare event in patients with medullary carcinoma, quite clearly such an occurrence is possible. Medullary carcinoma should be considered in the differential diagnosis of patients with metastatic bone lesions

    Childhood-onset schizophrenia: biological markers in relation to clinical characteristics

    No full text
    OBJECTIVE: The purpose of this study was to examine the relationships between clinical and neurobiological measures of childhood-onset schizophrenia. It was hypothesized that there would be a more striking pattern in the rare cases with very early onset than is seen in subjects with later onset. METHOD: Premorbid, clinical, prenatal, perinatal, and magnetic resonance imaging brain measures were examined in 29 children and adolescents who met the DSM-III-R criteria for schizophrenia with onset before age 12. Specifically, gender, premorbid adjustment, and clinical symptoms were examined in relation to cerebral volume, ventricular volume, and maternal obstetrical complications. RESULTS: Males were more likely to have had an insidious onset than females. There was a significant negative correlation between score on the Scale for the Assessment of Negative Symptoms and total cerebral volume. CONCLUSIONS: These neurobiological associations support the continuity of early-onset schizophrenia with the later-onset disorder; the striking association between smaller cerebral volume and negative symptoms suggests a more homogeneous or more potent neurobiological basis for very early-onset schizophrenia

    Abnormal neurologic maturation in adolescents with early-onset schizophrenia

    No full text
    OBJECTIVE: This study evaluated neurologic functioning in adolescents with schizophrenia with onset of psychosis before age 13. METHOD: The authors administered a structured neurologic examination to 21 adolescents with early-onset schizophrenia and 27 healthy age- and sex-matched comparison subjects. RESULTS: The adolescents with schizophrenia had a high frequency of neurologic abnormalities. Neurologic signs decreased with age in the healthy comparison subjects but not in the subjects with schizophrenia. CONCLUSIONS: The adolescents with schizophrenia had a high burden of neurologic impairment and a pattern of abnormalities similar to that of adults with schizophrenia. The persistence of neurologic signs in the adolescents with schizophrenia, which faded with age in the healthy comparison adolescents, supports earlier evidence of a delay in or failure of normal brain development during adolescence

    Quantitative magnetic resonance imaging of the corpus callosum in childhood onset schizophrenia

    No full text
    Corpus callosum size has been found to be abnormal in adult schizophrenia, and other studies have implicated abnormal interhemispheric communication in this disorder. To assess continuity with brain abnormalities in the later onset disorder and to further localize brain maldevelopment, this structure was examined in a unique sample of childhood onset schizophrenics. Anatomic brain magnetic resonance imaging scans were acquired for 25 patients (mean age 13.9 +/- 2.1) who had onset of schizophrenia by age 12 (mean age at onset 9.9 +/- 1.9) and 55 normal children. The midsagittal area of the corpus callosum was divided into seven sections. With no adjustment for brain volume, no diagnostic differences were observed. After adjustment for the smaller cerebral volume of the schizophrenics, larger total, anterior and posterior corpus callosum areas emerged for the schizophrenics. These findings provide further evidence for continuity between childhood onset and later onset schizophrenia and support other studies showing white matter sparing in the context of decreased cortical volume

    Pubertal development and onset of psychosis in childhood onset schizophrenia

    No full text
    In this study, pubertal development was examined for a sample of children and adolescents with childhood onset schizophrenia (COS) defined as psychosis by age 12. Developmental and psychiatric histories were obtained for 28 adolescents (mean age 14.5 +/- 2.3 years) with severe, treatment refractory COS (14 males, 14 females). Age of onset of psychosis was also examined in relation to menarche and development of secondary sex characteristics. Girls had a trend towards developing secondary sex characteristics earlier than boys (P = 0.06), consistent with North American norms. Males (N = 14) and females (N = 14) had similar age of onset of psychosis. The age of development of secondary sex characteristics was associated with onset of psychosis for girls, but this finding was driven by one outlier. There was no significant correlation between development of psychosis and menarche. Neither male nor female probands differed significantly from their well siblings or from North American norms in their age of onset of pubertal development. There was no evidence of early onset of secondary sex characteristics for this sample. Finally, there was an absence of a clear relationship between onset of psychosis and indices of sexual development for these very early onset cases
    corecore