196 research outputs found

    Ecology of the Oceanic Rim: Pelagic Eels as Key Ecosystem Components

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    Although 92% of the total volume of the world’s oceans occurs below a depth of 200 m, our understanding of deep-sea food webs lags far behind that of continental shelves. In particular, little is known about the exchange of biomass at the interface of continental margins and deep-sea ecosystems. Recent studies suggest that the transport of organic matter from continental shelves may influence deep-sea ecosystems more than previously thought. Here, we present results of a pelagic nekton survey along the southern slope of Georges Bank, NW Atlantic, a transition area between coastal and deep-sea environments. Specimens were collected as part of the Census of Marine Life program Gulf of Maine Area project. Macrocrustacea (primarily sergestid shrimps and large euphausiids) dominated the total nekton (all taxa) numbers and biomass. Of the 85 deep-pelagic fish species collected during this cruise, the slender snipe eel Nemichthys scolopaceus (Anguilliformes: Nemichthyidae) ranked first in biomass and second in abundance. Microscopic analysis of N. scolopaceus gut contents revealed a predominance of large euphausiid and decapod prey. Other abundant potential prey, such as zooplankton, fish, and cephalopods, were absent from the diet, suggesting discriminatory feeding. Considering the relative biomass dominance of sergestid shrimps, large euphausiids, and pelagic eels in this system, the ecological interaction described here likely represents a major trophic pathway in this and similar ‘oceanic rim’ ecosystems

    Mechanisms Driving the Effect of Weight Loss on Arterial Stiffness

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    Aims Arterial stiffness decreases with weight loss in overweight and obese adults, but the mechanisms by which this occurs are poorly understood. We aimed to elucidate these mechanisms. Methods We evaluated carotid-femoral pulse wave velocity (cfPWV), a measure of aortic stiffness, and brachial-ankle pulse wave velocity (baPWV), a mixed measure of central and peripheral arterial stiffness, in 344 young adults (mean age 38 yrs, mean body mass index (BMI) 32.9 kg/m2, 23% male) at baseline, 6 and 12 months in a behavioral weight loss intervention. Linear mixed effects models were used to evaluate associations between weight loss and arterial stiffness and to examine the degree to which improvements in obesity-related factors explained these associations. Pattern-mixture models using indicator variables for dropout pattern and Markov Chain Monte Carlo multiple imputation were used to evaluate the influence of different missing data assumptions. Results At 6 months (7% mean weight loss from baseline), there was a statistically significant median decrease of 47.5 cm/s (interquartile range (IQR) -44.5, 148) in cfPWV (p<0.0001) and a mean decrease of 11.7 cm/s (standard deviation (SD) 91.4) in baPWV (p=0.049). At 12 months (6% mean weight loss from baseline) only cfPWV remained statistically significantly reduced from baseline (p=0.02). Change in BMI (p=0.01) was statistically significantly positively associated with change in cfPWV after adjustment for changes in mean arterial pressure (MAP) or any other measured obesity-related factor. Common carotid artery diameter (p=0.003) was associated and heart rate (p=0.08) and MAP (p=0.07) marginally associated longitudinally with cfPWV. Reductions in heart rate (p<0.0001) and C-reactive protein (p=0.02) were associated with reduced baPWV, and each removed the statistical significance of the effect of weight loss on baPWV. Pattern-mixture modeling revealed several differences between completers and non-completers in the models for cfPWV, but marginal parameter estimates changed little from the original models for either PWV measure. Conclusions The public health importance of this thesis is that firstly, weight loss improves arterial stiffness in overweight and obese young adults. Secondly, its effect on baPWV may be explained by concurrent reductions in heart rate and inflammation. Missing data did not appear to bias these results

    Quantitative Proteomic Analysis of the Effect of Fluoride on the Acquired Enamel Pellicle

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    The acquired enamel pellicle (AEP) is a thin film formed by the selective adsorption of salivary proteins onto the enamel surface of teeth. The AEP forms a critical interface between the mineral phase of teeth (hydroxyapatite) and the oral microbial biofilm. This biofilm is the key feature responsible for the development of dental caries. Fluoride on enamel surface is well known to reduce caries by reducing the solubility of enamel to acid. Information on the effects of fluoride on AEP formation is limited. This study aimed to investigate the effects of fluoride treatment on hydroxyapatite on the subsequent formation of AEP. In addition, this study pioneered the use of label-free quantitative proteomics to better understand the composition of AEP proteins. Hydroxyapatite discs were randomly divided in 4 groups (n = 10 per group). Each disc was exposed to distilled water (control) or sodium fluoride solution (1, 2 or 5%) for 2 hours. Discs were then washed and immersed in human saliva for an additional 2 hours. AEP from each disc was collected and subjected to liquid chromatography electrospray ionization mass spectrometry for protein identification, characterization and quantification. A total of 45 proteins were present in all four groups, 12 proteins were exclusively present in the control group and another 19 proteins were only present in the discs treated with 5% sodium fluoride. Relative proteomic quantification was carried out for the 45 proteins observed in all four groups. Notably, the concentration of important salivary proteins, such as statherin and histatin 1, decrease with increasing levels of fluoride. It suggests that these proteins are repulsed when hydroxyapatite surface is coated with fluoride. Our data demonstrated that treatment of hydroxyapatite with fluoride (at high concentration) qualitatively and quantitatively modulates AEP formation, effects which in turn will likely impact the formation of oral biofilms.Natural Sciences and Engineering Research Council of Canada (NSERC) [371813]Natural Sciences and Engineering Research Council of Canada (NSERC)Canadian Institutes of Health Research (CIHR)Canadian Institutes of Health Research (CIHR) [106657, 97577]Canada Foundation for Innovation - Leaders Opportunity Fund (CFI-LOF) [25116]Canada Foundation for Innovation Leaders Opportunity Fund (CFILOF)CIHR New Investigator AwardCIHR New Investigator Award [113166

    Efficacy of a Smoking Cessation Intervention for Survivors of Cervical Intraepithelial Neoplasia or Cervical Cancer: A Randomized Controlled Trial

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    PURPOSE: Women who smoke and have a history of cervical intraepithelial neoplasia (CIN) or cervical cancer represent a vulnerable subgroup at elevated risk for recurrence, poorer cancer treatment outcomes, and decreased quality of life. The purpose of this study was to evaluate the long-term efficacy of Motivation And Problem Solving (MAPS), a novel treatment well-suited to meeting the smoking cessation needs of this population. METHODS: Women who were with a history of CIN or cervical cancer, age 18 years and older, spoke English or Spanish, and reported current smoking (≥100 lifetime cigarettes plus any smoking in the past 30 days) were eligible. Participants (N = 202) were recruited in clinic in Oklahoma City and online nationally and randomly assigned to (1) standard treatment (ST) or (2) MAPS. ST consisted of repeated referrals to a tobacco cessation quitline, self-help materials, and combination nicotine replacement therapy (patch plus lozenge). MAPS comprised all ST components plus up to six proactive telephone counseling sessions over 12 months. Logistic regression and generalized estimating equations evaluated the intervention. The primary outcome was self-reported 7-day point prevalence abstinence from tobacco at 18 months, with abstinence at 3, 6, and 12 months and biochemically confirmed abstinence as secondary outcomes. RESULTS: There was no significant effect for MAPS over ST at 18 months (14.2% CONCLUSION: MAPS led to a greater than two-fold increase in smoking abstinence among survivors of CIN and cervical cancer at 12 months. At 18 months, abstinence in MAPS declined to match the control condition and the treatment effect was no longer significant

    Rare Variant Enrichment analysis Supports

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    Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is characterized by aplasia of the female reproductive tract; the syndrome can include renal anomalies, absence or dysgenesis, and skeletal anomalies. While functional models have elucidated several candidate genes, onl

    Rare Variant Enrichment Analysis Supports GREB1L as a Contributory Driver Gene in the Etiology of Mayer-Rokitansky-Küster-Hauser Syndrome

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    Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is characterized by aplasia of the female reproductive tract; the syndrome can include renal anomalies, absence or dysgenesis, and skeletal anomalies. While functional models have elucidated several candidate genes, only WNT4 (MIM: 603490) variants have been definitively associated with a subtype of MRKH with hyperandrogenism (MIM: 158330). DNA from 148 clinically diagnosed MRKH probands across 144 unrelated families and available family members from North America, Europe, and South America were exome sequenced (ES) and by family-based genomics analyzed for rare likely deleterious variants. A replication cohort consisting of 442 Han Chinese individuals with MRKH was used to further reproduce GREB1L findings in diverse genetic backgrounds. Proband and OMIM phenotypes annotated using the Human Phenotype Ontology were analyzed to quantitatively delineate the phenotypic spectrum associated with GREB1L variant alleles found in our MRKH cohort and those previously published. This study reports 18 novel GREB1L variant alleles, 16 within a multiethnic MRKH cohort and two within a congenital scoliosis cohort. Cohort-wide analyses for a burden of rare variants within a single gene identified likely damaging variants in GREB1L (MIM: 617782), a known disease gene for renal hypoplasia and uterine abnormalities (MIM: 617805), in 16 of 590 MRKH probands. GREB1L variant alleles, including a CNV null allele, were found in 8 MRKH type 1 probands and 8 MRKH type II probands. This study used quantitative phenotypic analyses in a worldwide multiethnic cohort to identify and strengthen the association of GREB1L to isolated uterine agenesis (MRKH type I) and syndromic MRKH type II

    Effects of an intensive behavioral weight loss intervention consisting of caloric restriction with or without physical activity on common carotid artery remodeling in severely obese adults

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    Obesity increases cardiovascular disease risk and adversely affects vascular structure and function. Few studies have evaluated the vascular effects of non-surgical weight reduction in the severely obese. We hypothesized that weight loss and improvements in cardiometabolic factors would reduce common carotid artery intima-media thickness (CIMT) and inter-adventitial diameter (AD) in severely obese adults

    The Endogenous Th17 Response in NO<inf>2</inf>-Promoted Allergic Airway Disease Is Dispensable for Airway Hyperresponsiveness and Distinct from Th17 Adoptive Transfer

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    Severe, glucocorticoid-resistant asthma comprises 5-7% of patients with asthma. IL-17 is a biomarker of severe asthma, and the adoptive transfer of Th17 cells in mice is sufficient to induce glucocorticoid-resistant allergic airway disease. Nitrogen dioxide (NO2) is an environmental toxin that correlates with asthma severity, exacerbation, and risk of adverse outcomes. Mice that are allergically sensitized to the antigen ovalbumin by exposure to NO2 exhibit a mixed Th2/Th17 adaptive immune response and eosinophil and neutrophil recruitment to the airway following antigen challenge, a phenotype reminiscent of severe clinical asthma. Because IL-1 receptor (IL-1R) signaling is critical in the generation of the Th17 response in vivo, we hypothesized that the IL-1R/Th17 axis contributes to pulmonary inflammation and airway hyperresponsiveness (AHR) in NO2-promoted allergic airway disease and manifests in glucocorticoid-resistant cytokine production. IL-17A neutralization at the time of antigen challenge or genetic deficiency in IL-1R resulted in decreased neutrophil recruitment to the airway following antigen challenge but did not protect against the development of AHR. Instead, IL-1R-/- mice developed exacerbated AHR compared to WT mice. Lung cells from NO2-allergically inflamed mice that were treated in vitro with dexamethasone (Dex) during antigen restimulation exhibited reduced Th17 cytokine production, whereas Th17 cytokine production by lung cells from recipient mice of in vitro Th17-polarized OTII T-cells was resistant to Dex. These results demonstrate that the IL-1R/Th17 axis does not contribute to AHR development in NO2-promoted allergic airway disease, that Th17 adoptive transfer does not necessarily reflect an endogenously-generated Th17 response, and that functions of Th17 responses are contingent on the experimental conditions in which they are generated. © 2013 Martin et al

    Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing

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    A Class III Semaphorin (Sema3e) Inhibits Mouse Osteoblast Migration and Decreases Osteoclast Formation In Vitro

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    Originally identified as axonal guidance cues, semaphorins are expressed throughout many different tissues and regulate numerous non-neuronal processes. We demonstrate that most class III semaphorins are expressed in mouse osteoblasts and are differentially regulated by cell growth and differentiation: Sema3d expression is increased and Sema3e expression decreased during proliferation in culture, while expression of Sema3a is unaffected by cell density but increases in cultures of mineralizing osteoblasts. Expression of Sema3a, -3e, and -3d is also differentially regulated by osteogenic stimuli; inhibition of GSK3β decreased expression of Sema3a and -3e, while 1,25-(OH)2D3 increased expression of Sema3e. Parathyroid hormone had no effect on expression of Sema3a, -3b, or -3d. Osteoblasts, macrophages, and osteoclasts express the Sema3e receptor PlexinD1, suggesting an autocrine and paracrine role for Sema3e. No effects of recombinant Sema3e on osteoblast proliferation, differentiation, or mineralization were observed; but Sema3e did inhibit the migration of osteoblasts in a wound-healing assay. The formation of multinucleated, tartrate-resistant acid phosphatase–positive osteoclasts was decreased by 81% in cultures of mouse bone marrow macrophages incubated with 200 ng/mL Sema3e. Correspondingly, decreased expression of osteoclast markers (Itgb3, Acp5, Cd51, Nfatc1, CalcR, and Ctsk) was observed by qPCR in macrophage cultures differentiated in the presence of Sema3e. Our results demonstrate that class III semaphorins are expressed by osteoblasts and differentially regulated by differentiation, mineralization, and osteogenic stimuli. Sema3e is a novel inhibitor of osteoclast formation in vitro and may play a role in maintaining local bone homeostasis, potentially acting as a coupling factor between osteoclasts and osteoblasts
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