885 research outputs found

    Effects of changes in isotopic baselines on the evaluation of food web structure using isotopic functional indices

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    Background. This study aimed to assess whether ecological inferences from isotopic functional indices (IFIs) are impacted by changes in isotopic baselines in aquatic food webs. We used sudden CO2-outgassing and associated shifts in DIC- delta C-13 brought by waterfalls as an excellent natural experimental set-up to quantify impacts of changes in algal isotopic baselines on ecological inferences from IFIs.Methods. Carbon (delta C-13) and nitrogen (delta N-15) stable isotopic ratios of invertebrate communities sharing similar structure were measured at above- and below-waterfall sampling sites from five rivers and streams in Southern Quebec (Canada). For each sampled invertebrate community, the six Laymans IFIs were then calculated in the delta-space (delta C-13 vs. delta N-15).Results. As expected, isotopic functional richness indices, measuring the overall extent of community trophic space, were strongly sensitive to changes in isotopic baselines unlike other IFIs. Indeed, other IFIs were calculated based on the distribution of species within delta-space and were not strongly impacted by changes in the vertical or horizontal distribution of specimens in the delta-space. Our results highlighted that IFIs exhibited different sensitivities to changes in isotopic baselines, leading to potential misinterpretations of IFIs in river studies where isotopic baselines generally show high temporal and spatial variabilities. The identification of isotopic baselines and their associated variability, and the use of independent trophic tracers to identify the actual energy pathways through food webs must be a prerequisite to IFIs-based studies to strengthen the reliability of ecological inferences of food web structural properties

    Functional diversity of chironomid communities in subarctic lakes across gradients in temperature and catchment characteristics

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    Northern ecosystems are experiencing rapid and large-scale changes driven by accelerated warming, which have profound effects on the terrestrial and freshwater biodiversity. A comprehensive understanding of the distribution of aquatic biodiversity of subarctic ecosystems is therefore needed to better predict future trajectories of their unique biodiversity. In this study, we examined the functional diversity of chironomid communities in subarctic lakes across a 1000 m-elevation gradient, reflecting gradual changes in temperature and landscape characteristics. Using fuzzy correspondence analyses, we investigated spatial variability in trait composition of chironomid communities from 100 lakes in northern Sweden, and tested the hypotheses that (1) climate directly and indirectly shapes chironomid trait composition across the studied gradient, and (2) that generalist taxa with smaller body size and broader food preferences are more able to persist in cold environments. Our results showed that complex interplays between direct (e.g. temperature) and indirect climate processes (e.g. elevation-driven changes in vegetation/habitats) affect the functional diversity of chironomid communities. Specifically, traits such as larval size, food preference and feeding habits were well separated along the gradient, and this pattern revealed that low elevation lakes with forested catchments tended to have more sediment-feeding taxa and larger larvae than those above the tree line. As expected, food resource availability in lakes is strongly linked to vegetation composition/cover, and traits related to resource exploitation in chironomid communities are therefore well constrained by landscape characteristics. Furthermore, our findings suggested that short life cycles could facilitate the development of viable population in northern and high-elevation lakes where the short ice-free period is a limiting factor, thus contradicting patterns showing smaller organisms in warmer environments reported for other invertebrates. As a consequence of climate warming, the highest elevation lakes in subarctic landscapes will likely lose their typical cold-adapted chironomid taxa along with their functional attributes leading to potential impacts on the food web structure and the overall functioning of northern lake ecosystems

    Ipilimumab, not just another anti-cancer therapy: hypophysitis as side effect illustrated by four case-reports

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    Ipilimumab is a monoclonal antibody that blocks cytotoxic T-lymphocyte antigen4 (CTLA-4), an inhibitory molecule typically expressed on T cells. Blockade of CTLA-4 induces an overall activation of T cells, including an immune-mediated anti-tumour response. Unfortunately, this broad T cell stimulation also causes immune-related adverse events (irAEs), such as dermatitis, colitis, hepatitis and hypophysitis. Ipilimumab is currently available in Belgium as a second line of treatment for patients with advanced melanoma, and is used at a dose of 3 mg/kg of body weight, although higher doses were previously used (up to 10 mg/kg). We performed a retrospective analysis to identify melanoma patients treated with ipilimumab at the Ghent University Hospital between 2010 and 2013. Data on symptoms, stage and timing of ipilimumab, response and adverse events were collected with a special attention to endocrine disturbances, going from a limited involvement of one endocrine axis to development of a hypophysitis. We identified a total of 39 patients with stage III (No. = 7) or stage IV (No. = 32) melanoma, who received a dose of 3 (No. = 31) or 10 (No. = 8) mg/kg. Six patients developed a severe form of irAEs, including one case of colitis (2 %), one case of sarcoidosis (2 %) and 4 cases (10 %) of hypophysitis. Hypophysitis developed between the second and fourth cycle of ipilimumab administration and was independent of the dose used. We describe four cases of involvement of the pituitary gland during treatment with ipilimumab. When managed with vigilant monitoring and high-dose corticosteroids, the acute symptoms resolve, but lifelong hormone substitution therapy can be necessary. Involvement of the pituitary axes is a severe side effect of treatment with ipilimumab with an urgent need for the correct medical intervention

    The addition of bevacizumab to standard chemotherapy in breast cancer : which patient benefits the most?

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    Bevacizumab, a humanized monoclonal antibody directed against vascular endothelial growth factor, is an effective and well-tolerated treatment option for patients with breast cancer. Bevacizumab has demonstrated a gain in progression-free survival and a trend towards an overall survival benefit in various subgroups of breast cancer. Given the lack of a predictive biomarker, we performed a literature search with regard to efficacy and tolerability of bevacizumab in different subgroups of breast cancer patients and in different settings. In the metastatic setting, the efficacy of bevacizumab has been most extensively studied and demonstrated in patients with triple-negative breast cancer, the most difficult-to-treat population among patients with advanced disease and also the group with the biggest need for new treatment options. Overall, bevacizumab is well tolerated with very few serious adverse events. Bevacizumab is also an active and feasible treatment option for patients above 70 years of age

    Contrast-enhanced ultrasonography in hepatosplenic sarcoidosis

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    We report a case of a 38-year-old woman with atypical pain in the left lower hemi-abdomen. On abdominal B-mode ultrasonography the liver was normal; the spleen showed multiple subcentimetric hypoechoic nodules. A multidetector CT-examination revealed multiple small low-attenuation nodules in the liver and the spleen, suggestive for metastatic disease. Contrast-enhanced ultrasound (CEUS) revealed two hypoechoic nodules in the liver that were visible in the portal phase and disappeared in the late phase. The focal splenic lesions were visible as irregular hypo-enhancing nodules. An MRI examination, including T1, T2 and contrast-enhanced images, could not confirm the exact nature of the lesions. A core biopsy of a splenic nodule yielded non-caseating epithelioid cell granulomas. Different complementary examinations were normal and hepatosplenic sarcoidosis was diagnosed. The pain in the left lower hemi-abdomen was ascribed to irritable bowel syndrome

    Quality of life and symptom intensity over time in people with cancer receiving palliative care : results from the international European Palliative Care Cancer Symptom study

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    Background People with advanced cancer experience multiple symptoms during their illness trajectory, which can fluctuate in intensity. Aim To describe the course of self-reported quality of life, emotional functioning, physical functioning and symptom intensity over time in cancer patients receiving palliative care. Design Longitudinal study with monthly assessments, using the EORTC QLQ-C15-PAL. Data were analysed (1) prospectively, from baseline to >= 8-month follow-up; and (2) retrospectively, by taking death as index date and comparing results from three cross-sectional subsamples at different stages of illness (time to death >= 6, 5-3 and 2-0 months). Linear mixed models were calculated. Setting/participants A total of 1739 patients (mean age 66, 50% male) from 30 palliative care centers in 12 countries were included. Results In prospective analyses, quality of life, functioning and symptoms-except nausea/vomiting-remained generally stable over time. In retrospective analyses, patients 2-0 months before death reported significantly lower quality of life and physical functioning scores than those 5-3 months before death, who in turn scored lower than those >= 6 months before death, suggesting progressive decline. Emotional functioning remained initially unchanged, but decreased in the last months. Pain, fatigue and appetite loss showed a stable increase in intensity towards death. Dyspnea, insomnia and constipation increased from 5-3 to 2-0 months before death. Nausea/vomiting only increased when comparing those >= 6 months before death with those 2-0 months before death. Conclusion While the prospective approach showed predominantly stable patterns for quality of life, functioning and symptom severity throughout study duration, retrospective analyses indicated that deterioration was already apparent before the terminal phase and accelerated close to death. Our findings support the importance of early symptom identification and treatment in this population, and highlight the need for further studies to explore what characterizes those with either lower or higher symptom burden at different time points towards death

    Diagnostic accuracy of urinary prostate protein glycosylation profiling in prostatitis diagnosis

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    Introduction: Although prostatitis is a common male urinary tract infection, clinical diagnosis of prostatitis is difficult. The developmental mechanism of prostatitis is not yet unraveled which led to the elaboration of various biomarkers. As changes in asparagine-linked-(N-)-glycosylation were observed between healthy volunteers (HV), patients with benign prostate hyperplasia and prostate cancer patients, a difference could exist in biochemical parameters and urinary N-glycosylation between HV and prostatitis patients. We therefore investigated if prostatic protein glycosylation could improve the diagnosis of prostatitis. Materials and methods: Differences in serum and urine biochemical markers and in total urine N-glycosylation profile of prostatic proteins were determined between HV (N = 66) and prostatitis patients (N = 36). Additionally, diagnostic accuracy of significant biochemical markers and changes in N-glycosylation was assessed. Results: Urinary white blood cell (WBC) count enabled discrimination of HV from prostatitis patients (P < 0.001). Urinary bacteria count allowed for discriminating prostatitis patients from HV (P < 0.001). Total amount of biantennary structures (urinary 2A/MA marker) was significantly lower in prostatitis patients compared to HV (P < 0.001). Combining the urinary 2A/MA marker and urinary WBC count resulted in an AUC of 0.79, 95% confidence interval (CI) = (0.70-0.89) which was significantly better than urinary WBC count (AUC = 0.70, 95% CI = [0.59-0.82], P = 0.042) as isolated test. Conclusions: We have demonstrated the diagnostic value of urinary N-glycosylation profiling, which shows great potential as biomarker for prostatitis. Further research is required to unravel the developmental course of prostatic inflammation

    'A palliative end-stage COPD patient does not exist' : a qualitative study of barriers to and facilitators for early integration of palliative home care for end-stage COPD

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    Early integration of palliative home care (PHC) might positively affect people with chronic obstructive pulmonary disease (COPD). However, PHC as a holistic approach is not well integrated in clinical practice at the end-stage COPD. General practitioners (GPs) and community nurses (CNs) are highly involved in primary and home care and could provide valuable perspectives about barriers to and facilitators for early integrated PHC in end-stage COPD. Three focus groups were organised with GPs (n = 28) and four with CNs (n = 28), transcribed verbatim and comparatively analysed. Barriers were related to the unpredictability of COPD, a lack of disease insight and resistance towards care of the patient, lack of cooperation and experience with PHC for professional caregivers, lack of education about early integrated PHC, insufficient continuity of care from hospital to home, and lack of communication about PHC between professional caregivers and with end-stage COPD patients. Facilitators were the use of trigger moments for early integrating PHC, such as after a hospital admission or when an end-stage COPD patient becomes oxygen-dependent or housebound, positive attitudes towards PHC in informal caregivers, more focus on early integration of PHC in professional caregivers' education, implementing advance care planning in healthcare and PHC systems, and enhancing communication about care and PHC. The results provide insights for clinical practice and the development of key components for successful practice in a phase 0-2 Early Integration of PHC for end-stage COPD (EPIC) trial, such as improving care integration, patients' disease insight and training PHC nurses in care for end-stage COPD
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