79 research outputs found

    Joint analysis of stressors and ecosystem services to enhance restoration effectiveness

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    With increasing pressure placed on natural systems by growing human populations, both scientists and resource managers need a better understanding of the relationships between cumulative stress from human activities and valued ecosystem services. Societies often seek to mitigate threats to these services through large-scale, costly restoration projects, such as the over one billion dollar Great Lakes Restoration Initiative currently underway. To help inform these efforts, we merged high-resolution spatial analyses of environmental stressors with mapping of ecosystem services for all five Great Lakes. Cumulative ecosystem stress is highest in near-shore habitats, but also extends offshore in Lakes Erie, Ontario, and Michigan. Variation in cumulative stress is driven largely by spatial concordance among multiple stressors, indicating the importance of considering all stressors when planning restoration activities. In addition, highly stressed areas reflect numerous different combinations of stressors rather than a single suite of problems, suggesting that a detailed understanding of the stressors needing alleviation could improve restoration planning. We also find that many important areas for fisheries and recreation are subject to high stress, indicating that ecosystem degradation could be threatening key services. Current restoration efforts have targeted high-stress sites almost exclusively, but generally without knowledge of the full range of stressors affecting these locations or differences among sites in service provisioning. Our results demonstrate that joint spatial analysis of stressors and ecosystem services can provide a critical foundation for maximizing social and ecological benefits from restoration investments. www.pnas.org/lookup/suppl/doi:10.1073/pnas.1213841110/-/DCSupplementa

    Mechanisms of Mycobacterium bovis, strain bacillus Calmette-Guerin, fibronectin attachment protein binding and internalization by bladder tumor cells

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    Instillation of Mycobacterium bovis strain bacillus Calmette-Guerin (BCG) is the most efficacious and widely used treatment for superficial bladder cancer. However, BCG treatments can induce toxicity in patients, leading to reduced anti-cancer effects and expensive patient care. In addition, long-term follow-up studies show a high rate of recurrence, approximately 70%. Previous studies from our laboratory have identified a conserved component of BCG, which mediates the binding of BCG to the bladder tumor cells, called Fibronectin Attachment Protein (FAP). In vitro studies identified a unique binding site necessary for FAP attachment to fibronectin and that FAP is sufficient to induce anti-tumor activity in the bladder. These data suggest that FAP is a potential alternative to BCG and can be used to target bladder tumor cells for therapy. The goal of this project is to develop effective therapeutic approaches for the treatment of bladder cancer using FAP as a targeting agent. We hypothesized that FAP would function as an ideal targeting ligand for bladder tumor cells based on its ability to selectively associate with fibronectin that is uniquely exposed in bladder cancer. This was tested using immuno-fluorescent microscopy and flow cytometry to detect FAP binding and internalization in bladder tumor cell lines and in vivo tumors. We also evaluated the endocytic trafficking and end-point localization of FAP. Furthermore, we determined the ability of FAP-modified liposomes to bind to tumor cells and deliver therapeutic agents for the treatment of bladder cancer. The data showed that FAP is co-localized with FN in vitro in the human T24 bladder tumor cell line and the mouse 3T3 embryonic fibroblastic cell line. Co-localization studies with rhodamine-dextran and early endosomes suggest that FAP is internalized, but to a small extent, possibly by clathrin-mediated endocytosis. Studies using flow cytometry to determine the internalized fraction of FAP also confirm that FAP is internalized at a slow rate. Studies using FAP-conjugated liposomes showed variable results, with FAP enhancing liposomal delivery in approximately 50% of experiments

    Navigational tunnel technique for gastric peroral endoscopic pyloromyotomy: getting straight to the point (pylorus).

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    Background and aimsGastric peroral endoscopic pyloromyotomy (G-POEM) is emerging as a treatment option for patients with gastroparesis. The most technically difficult part of the procedure is creating a submucosal tunnel in the gastric antrum, which can be directionally challenging. We describe a novel navigational tunneling method that guides submucosal dissection in the direction of the pylorus and helps to identify the pyloric landmarks.MethodsConsecutive patients from September to December 2020 who underwent G-POEM for symptomatic gastroparesis were included. All cases were confirmed by prolonged gastric emptying study. The navigational tunnel technique was performed as follows: (1) mucosal cautery markings were made to outline the tunnel starting 3 to 4 cm proximal to the pylorus, (2) submucosal injection was done at the level of the pylorus and extended backward to the incision point, and (3) submucosal dissection was carried out after the prior submucosal injection straight to the pylorus.ResultsSix patients with gastroparesis underwent G-POEM with the navigational tunneling technique. The average time for submucosal injection was 2 minutes and 42 seconds, and the average tunnel time was 15 minutes and 36 seconds. There were no adverse events. All patients reported significant improvement (50%-85%) in symptoms.ConclusionsThis novel navigational tunneling technique appears to guide and facilitate G-POEM by providing a visual path for submucosal dissection straight to the pylorus. It may increase efficiency, decreasing the need to repeatedly exit the tunnel to check direction and preventing nonproductive wandering. It may also help identify the pyloric ring within the tunnel

    Sphingolipids and cellular cholesterol homeostasis. Effect of ceramide on cholesterol trafficking and HMG CoA reductase activity.

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    We previously showed that degradation of cellular sphingomyelin (SM) by SMase C results in a greater stimulation of cholesterol translocation to endoplasmic reticulum, compared to its degradation by SMase D. Here we investigated the hypothesis that the effect of SMase C is partly due to the generation of ceramide, rather than due to depletion of SM alone. Inhibition of hydroxymethylglutaryl CoA reductase (HMGCR) activity was used as a measure of cholesterol translocation. Treatment of fibroblasts with SMase C resulted in a 90% inhibition of HMGCR, whereas SMase D treatment inhibited it by 29%. Treatment with exogenous ceramides, or increasing the endogenous ceramide levels also inhibited HMGCR by 60-80%. Phosphorylation of HMGCR was stimulated by SMase C or exogenous ceramide. The effects of ceramide and SMase D were additive, indicating the independent effects of SM depletion and ceramide generation. These results show that ceramide regulates sterol trafficking independent of cellular SM levels

    NCoR1 Mediates Papillomavirus E8^E2C Transcriptional Repression▿ †

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    The papillomavirus E2 open reading frame encodes the full-length E2 protein as well as an alternatively spliced product called E8^E2C. E8^E2C has been best studied for the high-risk human papillomaviruses, where it has been shown to regulate viral genome levels and, like the full-length E2 protein, to repress transcription from the viral promoter that directs the expression of the viral E6 and E7 oncogenes. The repression function of E8^E2C is dependent on the 12-amino-acid N-terminal sequence from the E8 open reading frame (ORF). In order to understand the mechanism by which E8^E2C mediates transcriptional repression, we performed an unbiased proteomic analysis from which we identified six high-confidence candidate interacting proteins (HCIPs) for E8^E2C; the top two are NCoR1 and TBLR1. We established an interaction of E8^E2C with an NCoR1/HDAC3 complex and demonstrated that this interaction requires the wild-type E8 open reading frame. Small interfering RNA (siRNA) knockdown studies demonstrated the involvement of NCoR1/HDAC3 in the E8^E2C-dependent repression of the viral long control region (LCR) promoter. Additional genetic work confirmed that the papillomavirus E2 and E8^E2C proteins repress transcription through distinct mechanisms

    Impact of different training modalities on high-density lipoprotein function in HFpEF patients: a substudy of the OptimEx trial

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    Aims In heart failure with preserved ejection fraction (HFpEF), the reduction of nitric oxide (NO)-bioavailability and consequently endothelial dysfunction leads to LV stiffness and diastolic dysfunction of the heart. Besides shear stress, high-density lipoprotein (HDL) stimulates endothelial cells to increased production of NO via phosphorylation of endothelial nitric oxide synthase (eNOS). For patients with heart failure with reduced ejection fraction, earlier studies demonstrated a positive impact of exercise training (ET) on HDL-mediated eNOS activation. The study aims to investigate the influence of ET on HDL-mediated phosphorylation of eNOS in HFpEF patients. Methods and results The present study is a substudy of the OptimEx-Clin trial. The patients were randomized to three groups: (i) HIIT (high-intensity interval training; (ii) MCT (moderate-intensity continuous training); and (iii) CG (control group). Supervised training at study centres was offered for the first 3 months. From months 4–12, training sessions were continued at home with the same exercise protocol as performed during the in-hospital phase. Blood was collected at baseline, after 3, and 12 months, and HDL was isolated by ultracentrifugation. Human aortic endothelial cells were incubated with isolated HDL, and HDL-induced eNOS phosphorylation at Ser1177 and Thr495 was assessed. Subsequently, the antioxidative function of HDL was evaluated by measuring the activity of HDL-associated paraoxonase-1 (Pon1) and the concentration of thiobarbituric acid-reactive substances (TBARS). After 3 months of supervised ET, HIIT resulted in increased HDL-mediated eNOS-Ser1177 phosphorylation. This effect diminished after 12 months of ET. No effect of HIIT was observed on HDL-mediated eNOS-Thr495 phosphorylation. MCT had no effect on HDL-mediated eNOS phosphorylation at Ser1177 and Thr495. HIIT also increased Pon1 activity after 12 months of ET and reduced the concentration of TBARS in the serum after 3 and 12 months of ET. A negative correlation was observed between TBARS concentration and HDL-associated Pon1 activity in the HIIT group (r = −0.61, P < 0.05), and a trend was evident for the correlation between the change in HDL-mediated eNOS-Ser1177 phosphorylation and the change in peak V̇O2 after 3 months in the HIIT group (r = 0.635, P = 0.07). Conclusions The present study documented that HIIT but not MCT exerts beneficial effects on HDL-mediated eNOS phosphorylation and HDL-associated Pon1 activity in HFpEF patients. These beneficial effects of HIIT were reduced as soon as the patients switched to home-based ET
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