41 research outputs found

    Parity-induced decrease in systemic growth hormone alters mammary gland signaling: A potential role in pregnancy protection from breast cancer

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    Early full-term pregnancy is an effective natural protection against breast cancer in both humans and experimental rodents. The protective effect of an early pregnancy is in part linked to changes in circulating hormones that are involved in both normal breast development and breast cancer. For example, a reduction in circulating growth hormone (GH) has been shown to protect rats from carcinogen-induced mammary tumors. We examined the ability of a full-term pregnancy to alter the endocrine GH/IGF-I axis and how this change affected normal mammary gland function in two commonly used rat models (Sprague-Dawley and Wistar-Furth). Circulating GH and IGF-I were measured in blood drawn every 30 minutes from parous and aged-matched virgin (AMV) female rats. Mean serum GH levels were significantly decreased (

    Isolation of human monoclonal autoantibodies derived from pancreatic lymph node and peripheral blood B cells of islet autoantibody-positive patients

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    Aims/hypothesis Autoantibodies against pancreatic islets and infections by enteroviruses are associated with type 1 diabetes, but the specificity of immune responses within the type 1 diabetic pancreas is poorly characterised. We investigated whether pancreatic lymph nodes could provide a source of antigen-specific B cells for analysis of immune responses within the (pre)diabetic pancreas. Methods Human IgG antibodies were cloned from single B lymphocytes sorted from pancreatic lymph node cells of three organ donors positive for islet autoantibodies, and from the peripheral blood of a patient with type 1 diabetes. Antibodies to insulinoma-associated antigen 2 (IA-2), GAD65, zinc trans- porter 8 (ZnT8) and Coxsackie B virus proteins were assayed by immunoprecipitation and by immunofluorescence on pan- creatic sections. Results Human IgG antibodies (863) were successfully cloned and produced from 4,092 single B cells from lymph nodes and peripheral blood. Reactivity to the protein tyrosine phosphatase domain of the IA-2 autoantigen was detected in two cloned antibodies: one derived from a pancreatic lymph node and one from peripheral blood. Epitopes for these two antibodies were similar to each other and to those for circulat- ing antibodies in type 1 diabetes. The remaining 861 antibod- ies were negative for reactivity to IA-2, GAD65 or ZnT8 by both assays tested. Reactivity to a Coxsackie viral protein 2 was detected in one antibody derived from a peripheral blood B cell, but not from lymph nodes. Conclusions/interpretation We show evidence for the infre- quent presence of autoantigen-specific IgG+ B lymphocytes in the pancreatic-draining lymph nodes of islet autoantibody- positive individuals

    The clinical application of electrical impedance technology in the detection of malignant neoplasms: a systematic review

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    Background: Electrical impedance technology has been well established for the last 20 years. Recently research has begun to emerge into its potential uses in the detection and diagnosis of pre-malignant and malignant conditions. The aim of this study was to systematically review the clinical application of electrical impedance technology in the detection of malignant neoplasms. Methods: A search of Embase Classic, Embase and Medline databases was conducted from 1980 to 22/02/2018 to identify studies reporting on the use of bioimpedance technology in the detection of pre-malignant and malignant conditions. The ability to distinguish between tissue types was defined as the primary endpoint, and other points of interest were also reported. Results: 731 articles were identified, of which 51 reported sufficient data for analysis. These studies covered 16 different cancer subtypes in a total of 7035 patients. As the studies took various formats, a qualitative analysis of each cancer subtype’s data was undertaken. All the studies were able to show differences in electrical impedance and/or related metrics between malignant and normal tissue. Conclusions: Electrical impedance technology provides a novel method for the detection of malignant tissue, with large studies of cervical, prostate, skin and breast cancers showing encouraging results. Whilst these studies provide promising insights into the potential of this technology as an adjunct in screening, diagnosis and intra-operative margin assessment, customised development as well as multi-centre clinical trials need to be conducted before it can be reliably employed in the clinical detection of malignant tissue

    DNA methylation epigenotypes in breast cancer molecular subtypes

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    12 páginas, 3 figuras, 3 tablas.-- et al.[Introduction]: Identification of gene expression-based breast cancer subtypes is considered a critical means of prognostication. Genetic mutations along with epigenetic alterations contribute to gene-expression changes occurring in breast cancer. So far, these epigenetic contributions to sporadic breast cancer subtypes have not been well characterized, and only a limited understanding exists of the epigenetic mechanisms affected in those particular breast cancer subtypes. The present study was undertaken to dissect the breast cancer methylome and to deliver specific epigenotypes associated with particular breast cancer subtypes. [Methods]: By using a microarray approach, we analyzed DNA methylation in regulatory regions of 806 cancer-related genes in 28 breast cancer paired samples. We subsequently performed substantial technical and biologic validation by pyrosequencing, investigating the top qualifying 19 CpG regions in independent cohorts encompassing 47 basal-like, 44 ERBB2+ overexpressing, 48 luminal A, and 48 luminal B paired breast cancer/adjacent tissues. With the all-subset selection method, we identified the most subtype-predictive methylation profiles in multivariable logistic regression analysis. [Results]: The approach efficiently recognized 15 individual CpG loci differentially methylated in breast cancer tumor subtypes. We further identified novel subtype-specific epigenotypes that clearly demonstrate the differences in the methylation profiles of basal-like and human epidermal growth factor 2 (HER2)-overexpressing tumors. [Conclusions]: Our results provide evidence that well-defined DNA methylation profiles enable breast cancer subtype prediction and support the utilization of this biomarker for prognostication and therapeutic stratification of patients with breast cancer.This work was supported by grants from project CGL2008-01131 (Departamento de Sanidad del Gobierno Vasco), S-PE08UN45 and PE09BF02 (Departamento de Ciencia y Tecnologia del Gobierno Vasco), BIO2008-04212, and RD06/0020/1019 (Red Tematica de Investigacion Cooperativa en Cancer, RTICC) from the MICINN. The CIBER de Enfermedades Raras is an initiative of the ISCIII. NGB had a doctoral fellowship from the Basque Government (Departamento de Educacion, Universidades e Investigacion).Peer reviewe

    The effect of different levels of dry season supplementary feeding on the reproductive performance of yankasa sheep in a twice-yearly lambing programme

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    Ninety-four pregnant Yankasa ewes were divided into 3 groups and fed; (1) 0, (2) 200 or (3) 400 g/head/dat of a concentrate supplement in addition to 6 h grazing daily, from 35.9±2.0 days before, to 98. 1 ±2.0 days after lambing in the dry season between 2 Januuy and 15 May 1984 in Zaria, Northern Nigeria. There were no significant differences (P>0.05) between groups in litter size and adjusted birth weight in the initial lambing 35.9±2.0 days into the experiment although the latter showed consistent increase with level of supplementation. Adjusted 90- day weaning weights increued significantly (P<0.05) With eaeh increase in level of  upplementation: 5:5, 7.1 and 8 .6kg for groups 1, 2 and.3 respectively. Correspondingly, the percentage of lambs weaned increased (48.6, 56.4 and 90.7%) while ewe mortality declined (12.9, 10.0 and 3 .0%) With increasing level of supplementation. The percentage of ewes exhibiting oestrus Within 98.l ±2.0 days post-partum increased With level of supplementation: 77 .8, 91.3 and 96.8% for groups 1, 2 and 3 respectively. However, of the ewes showing oestrus, there were no significant differences between groups in post-partum intervals to oestrus and conception. Litter size from matings during the experiment showed non significant increase with level of supplementation. It is concluded that dry season supplementary feeding is essential for optimum reproductive performance of Yankasa sheep in a twice.yearly lambing programme.(Key Words: Levels, Dry Season, Supplementary, Feeding, Yankasa, Sheep)

    Parity-Induced Decrease in Systemic Growth Hormone Alters Mammary Gland Signaling: A Potential Role in Pregnancy Protection from Breast Cancer

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    Early full-term pregnancy is an effective natural protection against breast cancer in both humans and experimental rodents. The protective effect of an early pregnancy is in part linked to changes in circulating hormones that are involved in both normal breast development and breast cancer. For example, a reduction in circulating growth hormone (GH) has been shown to protect rats from carcinogen-induced mammary tumors. We examined the ability of a full-term pregnancy to alter the endocrine GH/IGF-I axis and how this change affected normal mammary gland function in two commonly used rat models (Sprague-Dawley and Wistar-Furth). Circulating GH and IGF-I were measured in blood drawn every 30 minutes from parous and aged-matched virgin (AMV) female rats. Mean serum GH levels were significantly decreased (p<0.01) in parous compared to AMV in both rat strains. Changes in GH levels were independent of estrous cycle, indicated by a significant (p<0.05) reduction in circulating levels of GH during estrus and diestrus in both parous strains. Despite the decrease in circulating GH, pituitary GH mRNA levels were unaltered in parous rats. Circulating IGF-I and hepatic IGF-I mRNA were also unaltered by parity in either rat strain. Immunoblot analysis of mammary glands showed decreases in phosphorylation of Stat5A and Jak2, suggesting reduced action of GH in the mammary gland. Therefore, while the parity reduction in circulating GH doesn’t impact upon circulating IGF-I levels, it is possible that reduced GH action directly at the mammary gland and may play a role in pregnancy protection from breast cancer

    Proinsulin-specific, HLA-DQ8, and HLA-DQ8-transdimer-restricted CD4(+) T cells infiltrate islets in type 1 diabetes

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    This article contains Supplementary Data online at http://diabetes.diabetesjournals.org/lookup/suppl/doi:10.2337/db14-0858/-/DC1Type 1 diabetes (T1D) develops when insulin-secreting β-cells, found in the pancreatic islets of Langerhans, are destroyed by infiltrating T cells. How human T cells recognize β-cell-derived antigens remains unclear. Genetic studies have shown that HLA and insulin alleles are the most strongly associated with risk of T1D. These long-standing observations implicate CD4(+) T-cell responses against (pro)insulin in the pathogenesis of T1D. To dissect the autoimmune T-cell response against human β-cells, we isolated and characterized 53 CD4(+) T-cell clones from within the residual pancreatic islets of a deceased organ donor who had T1D. These 53 clones expressed 47 unique clonotypes, 8 of which encoded proinsulin-specific T-cell receptors. On an individual clone basis, 14 of 53 CD4(+) T-cell clones (26%) recognized 6 distinct but overlapping epitopes in the C-peptide of proinsulin. These clones recognized C-peptide epitopes presented by HLA-DQ8 and, notably, HLA-DQ8 transdimers that form in HLA-DQ2/-DQ8 heterozygous individuals. Responses to these epitopes were detected in the peripheral blood mononuclear cells of some people with recent-onset T1D but not in HLA-matched control subjects. Hence, proinsulin-specific, HLA-DQ8, and HLA-DQ8-transdimer-restricted CD4(+) T cells are strongly implicated in the autoimmune pathogenesis of human T1D.Vimukthi Pathiraja, Janine P. Kuehlich, Peter D. Campbell, Balasubramanian Krishnamurthy, Thomas Loudovaris, P. Toby H. Coates, Thomas C. Brodnicki, Philip J. O, Connell, Katherine Kedzierska, Christine Rodda, Philip Bergman, Erin Hill, Anthony W. Purcell, Nadine L. Dudek, Helen E. Thomas, Thomas W.H. Kay, and Stuart I. Mannerin
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