273 research outputs found

    The effect of a protected area on the tradeoffs between short-run and long-run benefits from mangrove ecosystems

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    Protected areas are used to sustain biodiversity and ecosystem services. However, protected areas can create tradeoffs spatially and temporally among ecosystem services, which can affect the welfare of dependent local communities. This study examines the effect of a protected area on the tradeoff between two extractive ecosystem services from mangrove forests: cutting mangroves (fuelwood) and harvesting the shrimp and fish that thrive if mangroves are not cut. We demonstrate the effect in the context of Saadani National Park (SANAPA) in Tanzania, where enforcement of prohibition of mangrove harvesting was strengthened to preserve biodiversity. Remote sensing data of mangrove cover over time are integrated with georeferenced household survey data in an econometric framework to identify the causal effect of mangrove protection on income components directly linked to mangrove ecosystem services. Our findings suggest that many households experienced an immediate loss in the consumption of mangrove firewood, with the loss most prevalent in richer households. However, all wealth classes appear to benefit from long-term sustainability gains in shrimping and fishing that result from mangrove protection. On average, we find that a 10% increase in the mangrove cover within SANAPA boundaries in a 5-km2 radius of the subvillage increases shrimping income by approximately twofold. The creation of SANAPA shifted the future trajectory of the area from one in which mangroves were experiencing uncontrolled cutting to one in which mangrove conservation is providing gains in income for the local villages as a result of the preservation of nursery habitat and biodiversity

    Does local implantation of gentamicin impair renal function in patients undergoing surgery for chronic bone infection?

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    Background: The treatment of chronic bone infection often involves excision of dead bone and implantation of biomaterials which elute antibiotics. Gentamicin is a preferred drug for local delivery, but its systemic use carries a well-established risk of nephrotoxicity.  We aim to establish the risk of acute kidney injury (AKI) with local delivery in a ceramic carrier.Methods: 163 patients with Cierny-Mader type 3 or 4 chronic osteomyelitis had a single-stage operation including filling of the osseous defect with a calcium sulphate-hydroxyapatite carrier containing gentamicin. Mean gentamicin dosing was 191.3 mg (maximum 525 mg). Glomerular filtration rate (GFR) was calculated pre-operatively and during the first seven days post-operatively. Renal impairment was graded using the chronic kidney disease (CKD) staging system, and AKI was assessed using the RIFLE criteria.Results: 155 cases had adequate data to allow calculation of pre- and post-operative GFR. 7 had pre-existing renal disease. 70 patients (45.2%) had a temporary GFR drop post-operatively, with the greatest decrease occurring at a mean of 3.06 days following surgery. Twenty cases had a >10% decline in GFR, but 12 resolved within 7 days. 7 patients transiently fell into the “Risk” category according to RIFLE criteria, but no patient had a change consistent with “Injury”, “Failure” or “Loss” of renal function and none had clinical signs of new acute renal impairment post-operatively. Conclusions: Renal function is not significantly affected by local implantation of gentamicin up to 525 mg. The presence of pre-existing renal disease is not a contraindication to local gentamicin therapy.

    miR-17 overexpression in cystic fibrosis airway epithelial cells decreases interleukin-8 production.

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    Interleukin (IL)-8 levels are higher than normal in cystic fibrosis (CF) airways, causing neutrophil infiltration and non-resolving inflammation. Overexpression of microRNAs that target IL-8 expression in airway epithelial cells may represent a therapeutic strategy for cystic fibrosis. IL-8 protein and mRNA were measured in cystic fibrosis and non-cystic fibrosis bronchoalveolar lavage fluid and bronchial brushings (n=20 per group). miRNAs decreased in the cystic fibrosis lung and predicted to target IL-8 mRNA were quantified in βENaC-transgenic, cystic fibrosis transmembrane conductance regulator (Cftr)-/- and wild-type mice, primary cystic fibrosis and non-cystic fibrosis bronchial epithelial cells and a range of cystic fibrosis versus non-cystic fibrosis airway epithelial cell lines or cells stimulated with lipopolysaccharide, Pseudomonas-conditioned medium or cystic fibrosis bronchoalveolar lavage fluid. The effect of miRNA overexpression on IL-8 protein production was measured. miR-17 regulates IL-8 and its expression was decreased in adult cystic fibrosis bronchial brushings, βENaC-transgenic mice and bronchial epithelial cells chronically stimulated with Pseudomonas-conditioned medium. Overexpression of miR-17 inhibited basal and agonist-induced IL-8 protein production in F508del-CFTR homozygous CFTE29o(-) tracheal, CFBE41o(-) and/or IB3 bronchial epithelial cells. These results implicate defective CFTR, inflammation, neutrophilia and mucus overproduction in regulation of miR-17. Modulating miR-17 expression in cystic fibrosis bronchial epithelial cells may be a novel anti-inflammatory strategy for cystic fibrosis and other chronic inflammatory airway diseases

    Rapidly Progressive Dementia Due to Mycobacterium neoaurum Meningoencephalitis

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    Dementia developed in a patient with widespread neurologic manifestations; she died within 5 months. Pathologic findings showed granulomatous inflammation with caseation necrosis, foreign body–type giant cells, and proliferative endarteritis with vascular occlusions. Broad-range polymerase chain reaction identified Mycobacterium neoaurum as the possible pathogen. Central nervous system infection by M. neoaurum may result in rapidly progressive dementia

    Novel nesprin-1 mutations associated with dilated cardiomyopathy cause nuclear envelope disruption and defects in myogenesis

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    Nesprins-1 and -2 are highly expressed in skeletal and cardiac muscle and together with SUN (Sad1p/UNC84)-domain containing proteins and lamin A/C form the LInker of Nucleoskeleton-and-Cytoskeleton (LINC) bridging complex at the nuclear envelope (NE). Mutations in nesprin-1/2 have previously been found in patients with autosomal dominant Emery-Dreifuss muscular dystrophy (EDMD) as well as dilated cardiomyopathy (DCM). In this study, three novel rare variants (R8272Q, S8381C and N8406K) in the C-terminus of the SYNE1 gene (nesprin-1) were identified in seven DCM patients by mutation screening. Expression of these mutants caused nuclear morphology defects and reduced lamin A/C and SUN2 staining at the NE. GST pull-down indicated that nesprin-1/lamin/SUN interactions were disrupted. Nesprin-1 mutations were also associated with augmented activation of the ERK pathway in vitro and in hearts in vivo. During C2C12 muscle cell differentiation, nesprin-1 levels are increased concomitantly with kinesin light chain (KLC-1/2) and immunoprecipitation and GST pull-down showed that these proteins interacted via a recently identified LEWD domain in the C-terminus of nesprin-1. Expression of nesprin-1 mutants in C2C12 cells caused defects in myoblast differentiation and fusion associated with dysregulation of myogenic transcription factors and disruption of the nesprin-1 and KLC-1/2 interaction at the outer nuclear membrane. Expression of nesprin-1Îą2 WT and mutants in zebrafish embryos caused heart developmental and conduction defects that varied in severity. These findings support a role for nesprin-1 in myogenesis and muscle disease, and uncover a novel mechanism whereby disruption of the LINC complex may contribute to the pathogenesis of DCM

    PKCθ links proximal T cell and Notch signaling through localized regulation of the actin cytoskeleton

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    Notch is a critical regulator of T cell differentiation and is activated through proteolytic cleavage in response to ligand engagement. Using murine myelin-reactive CD4 T cells, we demonstrate that proximal T cell signaling modulates Notch activation by a spatiotemporally constrained mechanism. The protein kinase PKCθ is a critical mediator of signaling by the T cell antigen receptor and the principal costimulatory receptor CD28. PKCθ selectively inactivates the negative regulator of F-actin generation, Coronin 1A, at the center of the T cell interface with the antigen presenting cell (APC). This allows for effective generation of the large actin-based lamellum required for recruitment of the Notch-processing membrane metalloproteinase ADAM10. Such enhancement of Notch activation is critical for efficient T cell proliferation and Th17 differentiation. We reveal a novel mechanism that, through modulation of the cytoskeleton, controls Notch activation at the T cell:APC interface thereby linking T cell receptor and Notch signaling pathways. DOI: http://dx.doi.org/10.7554/eLife.20003.00

    Sofosbuvir and Velpatasvir for HCV Genotype 2 and 3 Infection

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    BACKGROUND: In phase 2 trials, treatment with the combination of the nucleotide polymerase inhibitor sofosbuvir and the NS5A inhibitor velpatasvir resulted in high rates of sustained virologic response in patients chronically infected with hepatitis C virus (HCV) genotype 2 or 3. METHODS: We conducted two randomized, phase 3, open-label studies involving patients who had received previous treatment for HCV genotype 2 or 3 and those who had not received such treatment, including patients with compensated cirrhosis. In one trial, patients with HCV genotype 2 were randomly assigned in a 1:1 ratio to receive sofosbuvir-velpatasvir, in a once-daily, fixed-dose combination tablet (134 patients), or sofosbuvir plus weight-based ribavirin (132 patients) for 12 weeks. In a second trial, patients with HCV genotype 3 were randomly assigned in a 1:1 ratio to receive sofosbuvir-velpatasvir for 12 weeks (277 patients) or sofosbuvir-ribavirin for 24 weeks (275 patients). The primary end point for the two trials was a sustained virologic response at 12 weeks after the end of therapy. RESULTS: Among patients with HCV genotype 2, the rate of sustained virologic response in the sofosbuvir-velpatasvir group was 99% (95% confidence interval [CI], 96 to 100), which was superior to the rate of 94% (95% CI, 88 to 97) in the sofosbuvir-ribavirin group (P=0.02). Among patients with HCV genotype 3, the rate of sustained virologic response in the sofosbuvir-velpatasvir group was 95% (95% CI, 92 to 98), which was superior to the rate of 80% (95% CI, 75 to 85) in the sofosbuvir-ribavirin group (P CONCLUSIONS: Among patients with HCV genotype 2 or 3 with or without previous treatment, including those with compensated cirrhosis, 12 weeks of treatment with sofosbuvir-velpatasvir resulted in rates of sustained virologic response that were superior to those with standard treatment with sofosbuvir-ribavirin. (Funded by Gilead Sciences; ASTRAL-2 ClinicalTrials.gov number, NCT02220998; and ASTRAL-3, NCT02201953.)

    Therapeutic options for mucinous ovarian carcinoma

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    OBJECTIVE: Mucinous ovarian carcinoma (MOC) is an uncommon ovarian cancer histotype that responds poorly to conventional chemotherapy regimens. Although long overall survival outcomes can occur with early detection and optimal surgical resection, recurrent and advanced disease are associated with extremely poor survival. There are no current guidelines specifically for the systemic management of recurrent MOC. We analyzed data from a large cohort of women with MOC to evaluate the potential for clinical utility from a range of systemic agents. METHODS: We analyzed gene copy number (n = 191) and DNA sequencing data (n = 184) from primary MOC to evaluate signatures of mismatch repair deficiency and homologous recombination deficiency, and other genetic events. Immunohistochemistry data were collated for ER, CK7, CK20, CDX2, HER2, PAX8 and p16 (n = 117-166). RESULTS: Molecular aberrations noted in MOC that suggest a match with current targeted therapies include amplification of ERBB2 (26.7%) and BRAF mutation (9%). Observed genetic events that suggest potential efficacy for agents currently in clinical trials include: KRAS/NRAS mutations (66%), TP53 missense mutation (49%), RNF43 mutation (11%), ARID1A mutation (10%), and PIK3CA/PTEN mutation (9%). Therapies exploiting homologous recombination deficiency (HRD) may not be effective in MOC, as only 1/191 had a high HRD score. Mismatch repair deficiency was similarly rare (1/184). CONCLUSIONS: Although genetically diverse, MOC has several potential therapeutic targets. Importantly, the lack of response to platinum-based therapy observed clinically corresponds to the lack of a genomic signature associated with HRD, and MOC are thus also unlikely to respond to PARP inhibition

    Volunteer Bias in Recruitment, Retention, and Blood Sample Donation in a Randomised Controlled Trial Involving Mothers and Their Children at Six Months and Two Years: A Longitudinal Analysis

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    BACKGROUND: The vulnerability of clinical trials to volunteer bias is under-reported. Volunteer bias is systematic error due to differences between those who choose to participate in studies and those who do not. METHODS AND RESULTS: This paper extends the applications of the concept of volunteer bias by using data from a trial of probiotic supplementation for childhood atopy in healthy dyads to explore 1) differences between a) trial participants and aggregated data from publicly available databases b) participants and non-participants as the trial progressed 2) impact on trial findings of weighting data according to deprivation (Townsend) fifths in the sample and target populations. 1) a) Recruits (n = 454) were less deprived than the target population, matched for area of residence and delivery dates (n = 6,893) (mean [SD] deprivation scores 0.09[4.21] and 0.79[4.08], t = 3.44, df = 511, p<0.001). b) i) As the trial progressed, representation of the most deprived decreased. These participants and smokers were less likely to be retained at 6 months (n = 430[95%]) (OR 0.29,0.13-0.67 and 0.20,0.09-0.46), and 2 years (n = 380[84%]) (aOR 0.68,0.50-0.93 and 0.55,0.28-1.09), and consent to infant blood sample donation (n = 220[48%]) (aOR 0.72,0.57-0.92 and 0.43,0.22-0.83). ii) Mothers interested in probiotics or research or reporting infants' adverse events or rashes were more likely to attend research clinics and consent to skin-prick testing. Mothers participating to help children were more likely to consent to infant blood sample donation. 2) In one trial outcome, atopic eczema, the intervention had a positive effect only in the over-represented, least deprived group. Here, data weighting attenuated risk reduction from 6.9%(0.9-13.1%) to 4.6%(-1.4-+10.5%), and OR from 0.40(0.18-0.91) to 0.56(0.26-1.21). Other findings were unchanged. CONCLUSIONS: Potential for volunteer bias intensified during the trial, due to non-participation of the most deprived and smokers. However, these were not the only predictors of non-participation. Data weighting quantified volunteer bias and modified one important trial outcome. TRIAL REGISTRATION: This randomised, double blind, parallel group, placebo controlled trial is registered with the International Standard Randomised Controlled Trials Register, Number (ISRCTN) 26287422. Registered title: Probiotics in the prevention of atopy in infants and children
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