Elevated levels of Dickkopf-related protein 3 in seminal plasma of prostate cancer patients

<p>Abstract</p> <p>Background</p> <p>Expression of Dkk-3, a secreted putative tumor suppressor, is altered in age-related proliferative disorders of the human prostate. We now investigated the suitability of Dkk-3 as a diagnostic biomarker for prostate cancer (PCa) in seminal plasma (SP).</p> <p>Methods</p> <p>SP samples were obtained from 81 patients prior to TRUS-guided prostate biopsies on the basis of elevated serum prostate-specific antigen (PSA; > 4 ng/mL) levels and/or abnormal digital rectal examination. A sensitive indirect immunoenzymometric assay for Dkk-3 was developed and characterized in detail. SP Dkk-3 and PSA levels were determined and normalized to total SP protein. The diagnostic accuracies of single markers including serum PSA and multivariate models to discriminate patients with positive (N = 40) and negative (N = 41) biopsy findings were investigated.</p> <p>Results</p> <p>Biopsy-confirmed PCa showed significantly higher SP Dkk-3 levels (100.9 ± 12.3 vs. 69.2 ± 9.4 fmol/mg; <it>p </it>= 0.026). Diagnostic accuracy (AUC) of SP Dkk-3 levels (0.633) was enhanced in multivariate models by including serum PSA (model A; AUC 0.658) or both, serum and SP PSA levels (model B; AUC 0.710). In a subpopulation with clinical follow-up > 3 years post-biopsy to ensure veracity of negative biopsy status (positive biopsy N = 21; negative biopsy N = 25) AUCs for SP Dkk-3, model A and B increased to 0.667, 0.724 and 0.777, respectively.</p> <p>Conclusions</p> <p>In multivariate models to detect PCa, inclusion of SP Dkk-3 levels, which were significantly elevated in biopsy-confirmed PCa patients, improved the diagnostic performance compared with serum PSA only.</p

Operationalizing local ecological knowledge in climate change research : challenges and opportunities of citizen science

Current research on the local impacts of climate change is based on contrasting results from the simulation of historical trends in climatic variables produced with global models against climate data from independent observations. To date, these observations have mostly consisted of weather data from standardized meteorological stations. Given that the spatial distribution of weather stations is patchy, climate scientists have called for the exploration of new data sources. Knowledge developed by Indigenous Peoples and local communities with a long history of interaction with their environment has been proposed as a data source with untapped potential to contribute to our understanding of the local impacts of climate change. In this chapter, we discuss an approach that aims to bring insights from local knowledge systems to climate change research. First, we present a number of theoretical arguments that give support to the idea that local knowledge systems can contribute in original ways to the endeavors of climate change research. Then, we explore the potential of using information and communication technologies to gather and share local knowledge of climate change impacts. We do so through the examination of a citizen science initiative aiming to collect local indicators of climate change impacts: the LICCI project (www.licci.eu). Our findings illustrate that citizen science can inspire new approaches to articulate the inclusion of local knowledge systems in climate change research. However, this requires outlining careful approaches, with high ethical standards, toward knowledge validation and recognizing that there are aspects of local ecological knowledge that are incommensurable with scientific knowledge

Longitudinal assessment of climate vulnerability: a case study from the Canadian Arctic

The Arctic is a global hotspot of climate change, which is impacting the livelihoods of remote Inuit communities. We conduct a longitudinal assessment of climate change vulnerability drawing upon fieldwork conducted in 2004 and 2015 in Ikpiarjuk (Arctic Bay), Nunavut, and focusing on risks associated with subsistence harvesting activities. Specifically, we employ the same conceptual and methodological approach to identify and characterize who is vulnerable, to what stresses, and why, assessing how this has changed over time, including re-interviewing individuals involved in the original study. We find similarities between the two periods, with many of the observed environmental changes documented in 2004 having accelerated over the last decade, exacerbating risks of land use: changing sea ice regimes and wind patterns are the most widely documented at both times, with new observations reporting more frequent sighting of polar bear and orca. Socio-economic and technological changes have altered the context in climate change impacts are being experienced and responded to, both exacerbating and moderating vulnerabilities compared to 2004. The adoption of new technology, including GPS and widespread use of the internet, has helped land users manage changing conditions while sharing networks remain strong, despite concern noted in the 2004 study that they were weakening. Challenges around access to financial resources and concern over the incomplete transmission of some environmental knowledge and land skills to younger generations continue to increase sensitivity and limit adaptive capacity to changing climatic conditions