1,082 research outputs found

    Decontaminating terrestrial oil spills: A comparative assessment of dog fur, human hair, peat moss and polypropylene sorbents

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    Terrestrial oil spills have severe and continuing consequences for human communities and the natural environment. Sorbent materials are considered to be a first line of defense method for directly extracting oil from spills and preventing further contaminant spread, but little is known on the performance of sorbent products in terrestrial environments. Dog fur and human hair sorbent products were compared to peat moss and polypropylene sorbent to examine their relative e ectiveness in adsorbing crude oil from di erent terrestrial surfaces. Crude oil spills were simulated using standardized microcosm experiments, and contaminant adsorbency was measured as percentage of crude oil removed from the original spilled quantity. Sustainable-origin absorbents made from dog fur and human hair were equally e ective to polypropylene in extracting crude oil from nonand semi-porous land surfaces, with recycled dog fur products and loose-form hair showing a slight advantage over other sorbent types. In a sandy terrestrial environment, polypropylene sorbent was significantly better at adsorbing spilled crude oil than all other tested products

    Influence of shear stress magnitude and direction on atherosclerotic plaque composition

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    British Heart Foundation (BHF) grants (no. RG/11/13/29055 and PG/15/49/31595), awarded to R.K. and E.P. who are employed by Bioengineering and the MRC Clinical Sciences Centre at Imperial College London. The grants also supported R.M.P. and S.M.B. V.V.M. was supported by a BHF. PhD studentship

    The connexin 43 regulator rotigaptide reduces cytokine-induced cell death in human islets

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    Background: Intercellular communication mediated by cationic fluxes through the Connexin family of gap junctions regulates glucose-stimulated insulin secretion and beta cell defense against inflammatory stress. Rotigaptide (RG, ZP123) is a peptide analog that increases intercellular conductance in cardiac muscle cells by the prevention of dephosphorylation and thereby uncoupling of Connexin-43 (Cx43), possibly via action on unidentified protein phosphatases. For this reason, it is being studied in human arrhythmias. It is unknown if RG protects islet cell function and viability against inflammatory or metabolic stress, a question of considerable translational interest for the treatment of diabetes. Methods: Apoptosis was measured in human islets shown to express Cx43, treated with RG or the control peptide ZP119 and exposed to glucolipotoxicity or IL-1β + IFNɣ. INS-1 cells shown to lack Cx43 were used to examine if RG protected human islet cells via Cx43 coupling. To study the mechanisms of action of Cx43-independent effects of RG, NO, IkBα degradation, mitochondrial activity, ROS, and insulin mRNA levels were determined. Results: RG reduced cytokine-induced apoptosis ~40% in human islets. In Cx43-deficient INS-1 cells, this protective effect was markedly blunted as expected, but unexpectedly, RG still modestly reduced apoptosis, and improved mitochondrial function, insulin-2 gene levels, and accumulated insulin release. RG reduced NO production in Cx43-deficient INS-1 cells associated with reduced iNOS expression, suggesting that RG blunts cytokine-induced NF-κB signaling in insulin-producing cells in a Cx43-independent manner. Conclusion: RG reduces cytokine-induced cell death in human islets. The protective action in Cx43-deficient INS-1 cells suggests a novel inhibitory mechanism of action of RG on NF-κB signaling

    Bivariate genetic modelling of the response to an oral glucose tolerance challenge: A gene x environment interaction approach

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    AIMS/HYPOTHESIS: Twin and family studies have shown the importance of genetic factors influencing fasting and 2 h glucose and insulin levels. However, the genetics of the physiological response to a glucose load has not been thoroughly investigated. METHODS: We studied 580 monozygotic and 1,937 dizygotic British female twins from the Twins UK Registry. The effects of genetic and environmental factors on fasting and 2 h glucose and insulin levels were estimated using univariate genetic modelling. Bivariate model fitting was used to investigate the glucose and insulin responses to a glucose load, i.e. an OGTT. RESULTS: The genetic effect on fasting and 2 h glucose and insulin levels ranged between 40% and 56% after adjustment for age and BMI. Exposure to a glucose load resulted in the emergence of novel genetic effects on 2 h glucose independent of the fasting level, accounting for about 55% of its heritability. For 2 h insulin, the effect of the same genes that already influenced fasting insulin was amplified by about 30%. CONCLUSIONS/INTERPRETATION: Exposure to a glucose challenge uncovers new genetic variance for glucose and amplifies the effects of genes that already influence the fasting insulin level. Finding the genes acting on 2 h glucose independently of fasting glucose may offer new aetiological insight into the risk of cardiovascular events and death from all causes

    Bioavailability, Antipsoriatic Efficacy and Tolerability of a New Light Cream with Mometasone Furoate 0.1%

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    Mometasone furoate, a potent glucocorticoid (class III) with a favorable benefit/risk ratio, has emerged as a standard medication for the treatment of inflammatory skin disorders. The purpose of the investigation presented here was to determine the noninferiority of a topical mometasone formulation, a light cream (O/W 60/40 emulsion) with mometasone furoate 0.1% (water content of 33%) versus marketed comparators. Using the vasoconstrictor assay, a strong blanching effect of the new cream (called Mometasone cream) comparable to that of a mometasone comparator, a fatty cream with mometasone furoate 0.1%, could be demonstrated. Thus, the topical bioavailability of the active ingredient mometasone furoate (0.1%) was regarded to be similar for Mometasone cream and the mometasone comparator. Using the psoriasis plaque test, a strong antipsoriatic effect comparable to that of the mometasone comparator was found for Mometasone cream after 12 days of occlusive treatment. A nearly identical reduction in the mean infiltrate thickness and similar mean AUC values were noted with both formulations confirmed by clinical assessment data. The noninferiority of Mometasone cream to its active comparator with re-spect to the AUC of change to baseline in infiltrate thickness was demonstrated. Both medications were well tolerated. Overall, Mometasone cream and the mometasone comparator showed similar efficacy and tolerability. Mometasone cream, in addition to its high potency and good tolerability, provides the properties of a light cream, which might make this new medication particularly suitable for application on acutely inflamed and sensitive skin. Copyright (C) 2012 S. Karger AG, Base

    Altered expression of a putative progenitor cell marker DCAMKL1 in the rat gastric mucosa in regeneration, metaplasia and dysplasia

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    <p>Abstract</p> <p>Background</p> <p>Doublecortin and calcium/calmodulin-dependent protein kinase-like-1 (DCAMKL1) is a candidate marker for progenitor cells in the gastrointestinal mucosa. Lineage cells in the gastric mucosa are derived from progenitor cells, but this process can be altered after injury. Therefore, we explored DCAMKL1 expression under pathological conditions.</p> <p>Methods</p> <p>An immunohistochemical analysis was performed in rat stomach with acute superficial injury, chronic ulcer, intestinal metaplasia and dysplasia.</p> <p>Results</p> <p>DCAMKL1 was exclusively expressed in immature quiescent cells in the isthmus of normal fundic glands, where putative progenitor cells are thought to reside. DCAMKL1-positive cells and proliferating cells shed into the lumen after superficial injury and re-appeared during the regenerative process, mainly in the superficial mucosa. In the marginal mucosa around the active ulcer, parietal and chief cells diminished, foveolar hyperplasia was evident, and trefoil factor family 2 (TFF2)/spasmolytic polypeptide-expressing metaplasia (SPEM) emerged at the gland base. DCAMKL1 cells re-emerged in the deep mucosa juxtaposed with SPEM and proliferating cells. In the healing ulcer, the TFF2 cell population expanded and seemed to redifferentiate to chief cells, while proliferating cells and DCAMKL1 cells appeared above and below the TFF2 cells to promote healing. SPEM appeared and PCNA cells increased in the intestinalized mucosa, and DCAMKL1 was expressed in the proximity of the PCNA cells in the deep mucosa. DCAMKL1, PCNA and TFF2 were expressed in different dysplastic cells lining dilated glands near SPEM.</p> <p>Conclusion</p> <p>The ultrastructural appearance of DCAMKL1-positive cells and the expression patterns of DCAMKL1 in normal and pathological states indicate that the cells belong to a progenitor cell population. DCAMKL1 expression is closely associated with TFF2/SPEM cells after injury. DCAMKL1 cells repopulate close to proliferating, hyperplastic, metaplastic and dysplastic cells, and the progenitor zone shifts according to the pathological circumstances.</p

    Elevated Paracellular Glucose Flux across Cystic Fibrosis Airway Epithelial Monolayers Is an Important Factor for Pseudomonas aeruginosa Growth.

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    People with cystic fibrosis (CF) who develop related diabetes (CFRD) have accelerated pulmonary decline, increased infection with antibiotic-resistant Pseudomonas aeruginosa and increased pulmonary exacerbations. We have previously shown that glucose concentrations are elevated in airway surface liquid (ASL) of people with CF, particularly in those with CFRD. We therefore explored the hypotheses that glucose homeostasis is altered in CF airway epithelia and that elevation of glucose flux into ASL drives increased bacterial growth, with an effect over and above other cystic fibrosis transmembrane conductance regulator (CFTR)-related ASL abnormalities. The aim of this study was to compare the mechanisms governing airway glucose homeostasis in CF and non-CF primary human bronchial epithelial (HBE) monolayers, under normal conditions and in the presence of Ps. aeruginosa filtrate. HBE-bacterial co-cultures were performed in the presence of 5 mM or 15 mM basolateral glucose to investigate how changes in blood glucose, such as those seen in CFRD, affects luminal Ps. aeruginosa growth. Calu-3 cell monolayers were used to evaluate the potential importance of glucose on Ps. aeruginosa growth, in comparison to other hallmarks of the CF ASL, namely mucus hyperviscosity and impaired CFTR-dependent fluid secretions. We show that elevation of basolateral glucose promotes the apical growth of Ps. aeruginosa on CF airway epithelial monolayers more than non-CF monolayers. Ps. aeruginosa secretions elicited more glucose flux across CF airway epithelial monolayers compared to non-CF monolayers which we propose increases glucose availability in ASL for bacterial growth. In addition, elevating basolateral glucose increased Ps. aeruginosa growth over and above any CFTR-dependent effects and the presence or absence of mucus in Calu-3 airway epithelia-bacteria co-cultures. Together these studies highlight the importance of glucose as an additional factor in promoting Ps. aeruginosa growth and respiratory infection in CF disease

    Advances in prevention and therapy of neonatal dairy calf diarrhoea : a systematical review with emphasis on colostrum management and fluid therapy

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    Neonatal calf diarrhoea remains the most common cause of morbidity and mortality in preweaned dairy calves worldwide. This complex disease can be triggered by both infectious and non-infectious causes. The four most important enteropathogens leading to neonatal dairy calf diarrhoea are Escherichia coli, rota-and coronavirus, and Cryptosporidium parvum. Besides treating diarrhoeic neonatal dairy calves, the veterinarian is the most obvious person to advise the dairy farmer on prevention and treatment of this disease. This review deals with prevention and treatment of neonatal dairy calf diarrhoea focusing on the importance of a good colostrum management and a correct fluid therapy

    Exploring the relation between remotely sensed vertical canopy structure and tree species diversity in Gabon

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    Mapping tree species diversity is increasingly important in the face of environmental change and biodiversity conservation. We explore a potential way of mapping this diversity by relating forest structure to tree species diversity in Gabon. First, we test the relation between canopy height, as a proxy for niche volume, and tree species diversity. Then, we test the relation between vertical canopy structure, as a proxy for vertical niche occupation, and tree species diversity. We use large footprint full-waveform airborne lidar data collected across four study sites in Gabon (Lopé, Mabounié, Mondah, and Rabi) in combination with in situ estimates of species richness (S) and Shannon diversity (H'). Linear models using canopy height explained 44% and 43% of the variation in S and H' at the 0.25 ha resolution. Linear models using canopy height and the plant area volume density profile explained 71% of this variation. We demonstrate applications of these models by mapping S and H' in Mondah using a simulated GEDI-TanDEM-X fusion height product, across the four sites using wall-to-wall airborne lidar data products, and across and between the study sites using ICESat lidar waveforms. The modeling results are encouraging in the context of developing pan-tropical structure-diversity models applicable to data from current and upcoming spaceborne remote sensing missions
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