395 research outputs found

    A new human chromogranin A (CgA) immunoradiometric assay involving monoclonal antibodies raised against the unprocessed central domain (145-245)

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    Chromogranin A (CgA), a major protein of chromaffin granules, has been described as a potential marker for neuroendocrine tumours. Because of an extensive proteolysis which leads to a large heterogeneity of circulating fragments, its presence in blood has been assessed in most cases either by competitive immunoassays or with polyclonal antibodies. In the present study, 24 monoclonal antibodies were raised against native or recombinant human CgA. Their mapping with proteolytic peptides showed that they defined eight distinct epitopic groups which spanned two-thirds of the C-terminal part of human CgA. All monoclonal antibodies were tested by pair and compared with a reference radioimmunoassay (RIA) involving CGS06, one of the monoclonal antibodies against the 198–245 sequence. It appears that CgA C-terminal end seems to be highly affected by proteolysis and the association of C-terminal and median-part monoclonal antibodies is inadequate for total CgA assessment. Our new immunoradiometric assay involves two monoclonal antibodies, whose contiguous epitopes lie within the median 145–245 sequence. This assay allows a sensitive detection of total human CgA and correlates well with RIA because dibasic cleavage sites present in the central domain do not seem to be affected by degradation. It has been proved to be efficient in measuring CgA levels in patients with neuroendocrine tumours. © 1999 Cancer Research Campaig

    Naturally Occurring Genetic Variants in Human Chromogranin A (CHGA) Associated with Hypertension as well as Hypertensive Renal Disease

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    Chromogranin A (CHGA) plays a fundamental role in the biogenesis of catecholamine secretory granules. Changes in storage and release of CHGA in clinical and experimental hypertension prompted us to study whether genetic variation at the CHGA locus might contribute to alterations in autonomic function, and hence hypertension and its target organ consequences such as hypertensive renal disease (nephrosclerosis). Systematic polymorphism discovery across the human CHGA locus revealed both common and unusual variants in both the open reading frame and such regulatory regions as the proximal promoter and 3′-UTR. In chromaffin cell-transfected CHGA 3′-UTR and promoter/luciferase reporter plasmids, the functional consequences of the regulatory/non-coding allelic variants were documented. Variants in both the proximal promoter and the 3′-UTR displayed statistical associations with hypertension. Genetic variation in the proximal CHGA promoter predicted glomerular filtration rate in healthy twins. However, for hypertensive renal damage, both end-stage renal disease and rate of progression of earlier disease were best predicted by variants in the 3′-UTR. Finally, mechanistic studies were undertaken initiated by the clue that CHGA promoter variation predicted circulating endothelin-1. In cultured endothelial cells, CHGA triggered co-release of not only the vasoconstrictor and pro-fibrotic endothelin-1, but also the pro-coagulant von Willebrand Factor and the pro-angiogenic angiopoietin-2. These findings, coupled with stimulation of endothelin-1 release from glomerular capillary endothelial cells by CHGA, suggest a plausible mechanism whereby genetic variation at the CHGA locus eventuates in alterations in human renal function. These results document the consequences of genetic variation at the CHGA locus for cardiorenal disease and suggest mechanisms whereby such variation achieves functional effects

    Catestatin Improves Post-Ischemic Left Ventricular Function and Decreases Ischemia/Reperfusion Injury in Heart

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    The Chromogranin A (CgA)-derived anti-hypertensive peptide catestatin (CST) antagonizes catecholamine secretion, and is a negative myocardial inotrope acting via a nitric oxide-dependent mechanism. It is not known whether CST contributes to ischemia/reperfusion injury or is a component of a cardioprotective response to limit injury. Here, we tested whether CST by virtue of its negative inotropic activity improves post-ischemic cardiac function and cardiomyocyte survival. Three groups of isolated perfused hearts from adult Wistar rats underwent 30-min ischemia and 120-min reperfusion (I/R, Group 1), or were post-conditioned by brief ischemic episodes (PostC, 5-cycles of 10-s I/R at the beginning of 120-min reperfusion, Group 2), or with exogenous CST (75 nM for 20 min, CST-Post, Group-3) at the onset of reperfusion. Perfusion pressure and left ventricular pressure (LVP) were monitored. Infarct size was evaluated with nitroblue-tetrazolium staining. The CST (5 nM) effects were also tested in simulated ischemia/reperfusion experiments on cardiomyocytes isolated from young-adult rats, evaluating cell survival with propidium iodide labeling. Infarct size was 61 ± 6% of risk area in hearts subjected to I/R only. PostC reduced infarct size to 34 ± 5%. Infarct size in CST-Post was 36 ± 3% of risk area (P < 0.05 respect to I/R). CST-Post reduced post-ischemic rise of diastolic LVP, an index of contracture, and significantly improved post-ischemic recovery of developed LVP. In isolated cardiomyocytes, CST increased the cell viability rate by about 65% after simulated ischemia/reperfusion. These results suggest a novel cardioprotective role for CST, which appears mainly due to a direct reduction of post-ischemic myocardial damages and dysfunction, rather than to an involvement of adrenergic terminals and/or endothelium

    Deformation-related volcanism in the Pacific Ocean linked to the Hawaiian-Emperor bend

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    Ocean islands, seamounts and volcanic ridges are thought to form above mantle plumes. Yet, this mechanism cannot explain many volcanic features on the Pacific Ocean floor and some might instead be caused by cracks in the oceanic crust linked to the reorganization of plate motions. A distinctive bend in the Hawaiian–Emperor volcanic chain has been linked to changes in the direction of motion of the Pacific Plate, movement of the Hawaiian plume, or a combination of both. However, these links are uncertain because there is no independent record that precisely dates tectonic events that affected the Pacific Plate. Here we analyse the geochemical characteristics of lava samples collected from the Musicians Ridges, lines of volcanic seamounts formed close to the Hawaiian–Emperor bend. We find that the geochemical signature of these lavas is unlike typical ocean island basalts and instead resembles mid-ocean ridge basalts. We infer that the seamounts are unrelated to mantle plume activity and instead formed in an extensional setting, due to deformation of the Pacific Plate. 40Ar/39Ar dating reveals that the Musicians Ridges formed during two time windows that bracket the time of formation of the Hawaiian–Emperor bend, 53–52 and 48–47 million years ago. We conclude that the Hawaiian–Emperor bend was formed by plate–mantle reorganization, potentially triggered by a series of subduction events at the Pacific Plate margins

    Promoting regional development through a collaborative project in entrepreneurship education: lessons from a regional experiment to develop entrepreneurial competences in children and youngsters

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    The chapter focuses on the reflection around the relationship between entrepreneurial empowerment and regional development, based on the assumptions, methodology and results of a self-sustained supramunicipal project in entrepreneurship education, promoted by a wide network of partners representing all the municipalities of Baixo Alentejo, Portugal, and coordinated by the Polytechnic Institute of Beja (IPBeja). The project Promoting Entrepreneurship Education at the Schools of Baixo Alentejo (PEEBA) was carried out in collaboration with Elementary Schools (1st to 2nd Ciclos) and kindergartens of Baixo Alentejo with the objective to nurture entrepreneurial competencies in children and youngsters aged 3–12 through practical and experiential entrepreneurship education. It provided them with entrepreneurial skills and attitudes that will increase their opportunities, by helping them face their lives with more initiative and confidence and/or be more proactive at work, or even start their own business in a near future, in the hope that this may eventually contribute to reduce the brain drain in Baixo Alentejo. With the motto the socioeconomic future of our region will be shaped by the students we are educating now, the PEEBA is innovative and unique, since it consists in a platform that brings together all the key stakeholders in the field of entrepreneurship education within all the municipalities of a NUTS, in this particular case Baixo Alentejo, who show an interest in working collaboratively for a common goal: to create a shared ecosystem favourable to entrepreneurship and entrepreneurial capacity

    Catecholamine Storage Vesicles: Role of Core Protein Genetic Polymorphisms in Hypertension

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    Hypertension is a complex trait with deranged autonomic control of the circulation. The sympathoadrenal system exerts minute-to-minute control over cardiac output and vascular tone. Catecholamine storage vesicles (or chromaffin granules) of the adrenal medulla contain remarkably high concentrations of chromogranins/secretogranins (or “granins”), catecholamines, neuropeptide Y, adenosine triphosphate (ATP), and Ca2+. Within secretory granules, granins are co-stored with catecholamine neurotransmitters and co-released upon stimulation of the regulated secretory pathway. The principal granin family members, chromogranin A (CHGA), chromogranin B (CHGB), and secretogranin II (SCG2), may have evolved from shared ancestral exons by gene duplication. This article reviews human genetic variation at loci encoding the major granins and probes the effects of such polymorphisms on blood pressure, using twin pairs to probe heritability and individuals with the most extreme blood pressure values in the population to study hypertension

    Chromogranin A, a significant prognostic factor in small cell lung cancer

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    Chromogranin A (CgA) is a protein present in neuroendocrine vesicles. Small cell lung cancer (SCLC) is considered a neuroendocrine tumour. It is possible to demonstrate CgA expression in SCLC by immunohistochemical methods. Since CgA is released to the circulation it might also work as a clinical tumour marker. We used a newly developed two-site enzyme-linked immunosorbent assay for CgA in plasma from 150 newly diagnosed patients with SCLC. Follow-up was for a minimum of 5 years. Thirty-seven per cent of the patients had elevated pretreatment values and the values were significantly related to stage of disease. Multivariable analysis by Cox's proportional hazard model including nine known prognostic factors disclosed performance status as the most influential prognostic factor followed by stage of disease, CgA and LDH. A simple prognostic index (PI) could be established based on these four pretreatment features. In this way the patients could be separated into three groups with significant different prognosis. The median survival and 95% confidence intervals for the three groups were as follows: 424 days (311–537), 360 days (261–459) and 174 days (105–243). © 1999 Cancer Research Campaig

    A study protocol to investigate the management of depression and challenging behaviors associated with dementia in aged care settings

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    Background:&nbsp;The high occurrence and under-treatment of clinical depression and behavioral and psychological symptoms of dementia (BPSD) within aged care settings is concerning, yet training programs aimed at improving the detection and management of these problems have generally been ineffective. This article presents a study protocol to evaluate a training intervention for facility managers/registered nurses working in aged care facilities that focuses on organisational processes and culture as well as knowledge, skills and self-efficacy. Methods. A Randomised Control Trial (RCT) will be implemented across 18 aged care facilities (divided into three conditions). Participants will be senior registered nurses and personal care attendants employed in the aged care facility. The first condition will receive the training program (Staff as Change Agents - Enhancing and Sustaining Mental Health in Aged Care), the second condition will receive the training program and clinical support, and the third condition will receive no intervention. Results: Pre-, post-, 6-month and 12-month follow-up measures of staff and residents will be used to demonstrate how upskilling clinical leaders using our transformational training approach, as well as the use of a structured screening, referral and monitoring protocol, can address the mental health needs of older people in residential care. Conclusions: The expected outcome of this study is the validation of an evidence-based training program to improve the management of depression and BPSD among older people in residential care settings by establishing routine practices related to mental health. This relatively brief but highly focussed training package will be readily rolled out to a larger number of residential care facilities at a relatively low cost.</div

    A meta-analytic review of stand-alone interventions to improve body image

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    Objective Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image. Methods The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on improving body image), (b) a control group was used, (c) participants were randomly assigned to conditions, and (d) at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy. Results The literature search identified 62 tests of interventions (N = 3,846). Interventions produced a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies (d+ = -0.72). However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated. Conclusions The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions

    Teacher quality in the twenty first century: new lives, old truths

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    This chapter is based upon a keynote address to the first global teacher education summit, organised by Beijing Normal University in 2011, in which research across the world about influences which affect teachers' sense of professional identity, capacity for compassion, commitment, resilience and effectiveness long after they have graduated from their pre-service education and training programmes in universities and colleges were shared. The findings suggest that teaching pre-service students about how the conditions in which they work may enhance or diminish their capacity to teach to their best and how they might act to mediate these is a key part of the work of all teacher educators and an important focus for the work of educational researchers
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