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Heleen Nailis Tom Coenye Filip Van Nieuwerburgh Dieter Deforce Hans J Nelis 《BMC molecular biology》2006,7(1):25-9
Background
Candida albicans biofilms are commonly found on indwelling medical devices. However, the molecular basis of biofilm formation and development is not completely understood. Expression analysis of genes potentially involved in these processes, such as the ALS (Agglutinine Like Sequence) gene family can be performed using quantitative PCR (qPCR). In the present study, we investigated the expression stability of eight housekeeping genes potentially useful as reference genes to study gene expression in Candida albicans (C. albicans) biofilms, using the geNorm Visual Basic Application (VBA) for Microsoft Excel. To validate our normalization strategies we determined differences in ALS1 and ALS3 expression levels between C. albicans biofilm cells and their planktonic counterparts. 相似文献3.
Gabriela B. Gomez Nicola Foster Daniella Brals Heleen E. Nelissen Oladimeji A. Bolarinwa Marleen E. Hendriks Alexander C. Boers Diederik van Eck Nicole Rosendaal Peju Adenusi Kayode Agbede Tanimola M. Akande Michael Boele van Hensbroek Ferdinand W. Wit Catherine A. Hankins Constance Schultsz 《PloS one》2015,10(9)
Background
While the Nigerian government has made progress towards the Millennium Development Goals, further investments are needed to achieve the targets of post-2015 Sustainable Development Goals, including Universal Health Coverage. Economic evaluations of innovative interventions can help inform investment decisions in resource-constrained settings. We aim to assess the cost and cost-effectiveness of maternal care provided within the new Kwara State Health Insurance program (KSHI) in rural Nigeria.Methods and Findings
We used a decision analytic model to simulate a cohort of pregnant women. The primary outcome is the incremental cost effectiveness ratio (ICER) of the KSHI scenario compared to the current standard of care. Intervention cost from a healthcare provider perspective included service delivery costs and above-service level costs; these were evaluated in a participating hospital and using financial records from the managing organisations, respectively. Standard of care costs from a provider perspective were derived from the literature using an ingredient approach. We generated 95% credibility intervals around the primary outcome through probabilistic sensitivity analysis (PSA) based on a Monte Carlo simulation. We conducted one-way sensitivity analyses across key model parameters and assessed the sensitivity of our results to the performance of the base case separately through a scenario analysis. Finally, we assessed the sustainability and feasibility of this program’s scale up within the State’s healthcare financing structure through a budget impact analysis. The KSHI scenario results in a health benefit to patients at a higher cost compared to the base case. The mean ICER (US$46.4/disability-adjusted life year averted) is considered very cost-effective compared to a willingness-to-pay threshold of one gross domestic product per capita (Nigeria, US$ 2012, 2,730). Our conclusion was robust to uncertainty in parameters estimates (PSA: median US$49.1, 95% credible interval 21.9–152.3), during one-way sensitivity analyses, and when cost, quality, cost and utilization parameters of the base case scenario were changed. The sustainability of this program’s scale up by the State is dependent on further investments in healthcare.Conclusions
This study provides evidence that the investment made by the KSHI program in rural Nigeria is likely to have been cost-effective; however, further healthcare investments are needed for this program to be successfully expanded within Kwara State. Policy makers should consider supporting financial initiatives to reduce maternal mortality tackling both supply and demand issues in the access to care. 相似文献4.
Ann-Kristin Bergström;Irena F. Creed;Aleksey Paltsev;Heleen A. de Wit;Danny C. P. Lau;Stina Drakare;Tobias Vrede;Peter D. F. Isles;Anders Jonsson;Erik Geibrink;Pirkko Kortelainen;Jussi Vuorenmaa;Kristiina Vuorio;Kimmo K. Kahilainen;Dag Olav Hessen; 《Global Change Biology》2024,30(3):e17220
Zooplankton community composition of northern lakes is changing due to the interactive effects of climate change and recovery from acidification, yet limited data are available to assess these changes combined. Here, we built a database using archives of temperature, water chemistry and zooplankton data from 60 Scandinavian lakes that represent broad spatial and temporal gradients in key parameters: temperature, calcium (Ca), total phosphorus (TP), total organic carbon (TOC), and pH. Using machine learning techniques, we found that Ca was the most important determinant of the relative abundance of all zooplankton groups studied, while pH was second, and TOC third in importance. Further, we found that Ca is declining in almost all lakes, and we detected a critical Ca threshold in lake water of 1.3 mg L−1, below which the relative abundance of zooplankton shifts toward dominance of Holopedium gibberum and small cladocerans at the expense of Daphnia and copepods. Our findings suggest that low Ca concentrations may shape zooplankton communities, and that current trajectories of Ca decline could promote widespread changes in pelagic food webs as zooplankton are important trophic links from phytoplankton to fish and different zooplankton species play different roles in this context. 相似文献
5.
Van de Weerd HA Aarsen EL Mulder A Kruitwagen CL Hendriksen CF Baumans V 《Journal of applied animal welfare science : JAAWS》2002,5(2):87-109
This study focused on the effects of different enriched environments for mice in a number of behavioral and physiological parameters in 2 routine laboratory testing procedures: potency testing for tetanus vaccine and stress-induced hyperthermia. The variability in the results was studied by calculating and analyzing mean absolute deviations. Mice from enriched conditions weighed more and consumed more food than mice from standard housing conditions. However, mice from enriched conditions lost more body weight after being housed individually. Other physiological parameters showed no differences. Mice from standard conditions were more active in an open field, suggesting a tendency to overrespond to various stimuli in a testing environment. Mice from enriched environments were more tranquil and easier to handle. The enrichment did not influence the variability in any of the parameters measured, although earlier results and results of other studies suggest that the effects on the variability in results are parameter dependent. When enrichment does not influence variability, there is no reason for not introducing cage enrichment and by doing so contributing to the animals' welfare. 相似文献
6.
Roxanne I. van Giesen Arnout R. H. Fischer Heleen van Dijk Hans C. M. van Trijp 《PloS one》2015,10(10)
At large attitudes are built on earlier experience with the attitude object. If earlier experiences are not available, as is the case for unfamiliar attitude objects such as new technologies, no stored evaluations exist. Yet, people are still somehow able to construct attitudes on the spot. Depending on the familiarity of the attitude object, attitudes may find their basis more in affect or cognition. The current paper investigates differences in reliance on affect or cognition in attitude formation toward familiar and unfamiliar realistic attitude objects. In addition, individual differences in reliance on affect (high faith in intuition) or cognition (high need for cognition) are taken into account. In an experimental survey among Dutch consumers (N = 1870), we show that, for unfamiliar realistic attitude objects, people rely more on affect than cognition. For familiar attitude objects where both affective and cognitive evaluations are available, high need for cognition leads to more reliance on cognition, and high faith in intuition leads to more reliance on affect, reflecting the influence of individually preferred thinking style. For people with high need for cognition, cognition has a higher influence on overall attitude for both familiar and unfamiliar realistic attitude objects. On the other hand, affect is important for people with high faith in intuition for both familiar and unfamiliar attitude objects and for people with low faith in intuition for unfamiliar attitude objects; this shows that preferred thinking style is less influential for unfamiliar objects. By comparing attitude formation for familiar and unfamiliar realistic attitude objects, this research contributes to understanding situations in which affect or cognition is the better predictor of overall attitudes. 相似文献
7.
Sara Violante Lodewijk IJlst Heleen te Brinke Janet Koster Isabel Tavares de Almeida Ronald J.A. Wanders Fátima V. Ventura Sander M. Houten 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2013,1831(9):1467-1474
Fatty acid β-oxidation may occur in both mitochondria and peroxisomes. While peroxisomes oxidize specific carboxylic acids such as very long-chain fatty acids, branched-chain fatty acids, bile acids, and fatty dicarboxylic acids, mitochondria oxidize long-, medium-, and short-chain fatty acids. Oxidation of long-chain substrates requires the carnitine shuttle for mitochondrial access but medium-chain fatty acid oxidation is generally considered carnitine-independent. Using control and carnitine palmitoyltransferase 2 (CPT2)- and carnitine/acylcarnitine translocase (CACT)-deficient human fibroblasts, we investigated the oxidation of lauric acid (C12:0). Measurement of the acylcarnitine profile in the extracellular medium revealed significantly elevated levels of extracellular C10- and C12-carnitine in CPT2- and CACT-deficient fibroblasts. The accumulation of C12-carnitine indicates that lauric acid also uses the carnitine shuttle to access mitochondria. Moreover, the accumulation of extracellular C10-carnitine in CPT2- and CACT-deficient cells suggests an extramitochondrial pathway for the oxidation of lauric acid. Indeed, in the absence of peroxisomes C10-carnitine is not produced, proving that this intermediate is a product of peroxisomal β-oxidation. In conclusion, when the carnitine shuttle is impaired lauric acid is partly oxidized in peroxisomes. This peroxisomal oxidation could be a compensatory mechanism to metabolize straight medium- and long-chain fatty acids, especially in cases of mitochondrial fatty acid β-oxidation deficiency or overload. 相似文献
8.
Heleen M. Van der Maas E. R. de Jong A. C. Van Aelst H. A. Verhoeven F. A. Krens J. L. Van Went 《Protoplasma》1994,178(1-2):48-56
Summary The cytoplasmic content and the distribution of intramembrane particles (IMPs) of the plasma membrane of isolated sperm cells of perennial ryegrass (Lolium perenne L.) have been characterized using flow cytometry, transmission electron microscopy, confocal scanning laser microscopy and freeze-fracture studies. The isolated haploid sperm cells contain a variety of cell organelles with the exception of microtubules. Proplastids and plastids with starch were observed, although only rarely. Vacuoles containing remnants of organelles and stacked lamellae of endoplasmic reticulum with cytoplasmic inclusions were observed frequently, indicating that autophagy takes place. The number of mitochondria varies from 11 to 26 with an average of 17. Generally, the nucleus has a lobed shape and displays various interphasic stages of chromatin condensation. The analysis of the number of mitochondria and the nuclear state did not show evidence of sperm cell dimorphism. The cytological variability observed, could be explained by differences in developmental stages already present in vivo at the moment of isolation. No correlation between the number of mitochondria and the nuclear cross-sectioned area and/or the condensation state of the chromatin could be found. The density of intramembrane particles of the plasma membrane on the exoplasmic fracture face is more than twice that on the protoplasmic fracture face. That is the opposite of what was found for sporophytic cells of perennial ryegrass. These results are discussed in relation to the potential use of these cells for biotechnology and developmental studies. 相似文献
9.
Glucose-6-phosphate dehydrogenase activity has been localized ultrastructurally in fixed tissues. Activity was found in particular in association with ribosomes of granular endoplasmatic reticulum. Biochemical studies indicated that glucose-6-phosphate dehydrogenase activity is also present in the cytoplasm and in peroxisomes. Fixation may be held responsible for selective inactivation of part of glucose-6-phosphate dehydrogenase activity. In the present study, we applied the ferricyanide method for the demonstration of glucose-6-phosphate dehydrogenase activity in unfixed cryostat sections of rat liver in combination with the semipermeable membrane technique and in isolated rat liver parenchymal cells. Isolated liver parenchymal cells were permeabilized with 0.025% glutaraldehyde after NADP+ protection of the active site of glucose-6-phosphate dehydrogenase. This treatment resulted in only slight inactivation of glucose-6-phosphate dehydrogenase activity. The composition of the incubation medium was optimized on the basis of rapid light microscopical analysis of the formation of reddish-brown final reaction product in sections. With the optimized method, electron dense reaction product was observed in cryostat sections on granular endoplasmic reticulum, in mitochondria and at the cell border. However, the ultrastructural morphology was rather poor. In contrast, the morphology of incubated isolated cells was preserved much better. Electron dense precipitate was found on ribosomes of the granular endoplasmic reticulum, in peroxisomes and the cytoplasm, particularly at the periphery of cells. In conclusion, our ultrastructural study clearly demonstrates that it is essential to use mildly-fixed cells to allow detection of glucose-6-phosphate dehydrogenase activity in all cellular compartments where activity is present. 相似文献
10.
Michiel G. J. Balvers Kitty C. M. Verhoeckx Sabina Bijlsma Carina M. Rubingh Jocelijn Meijerink Heleen M. Wortelboer Renger F. Witkamp 《Metabolomics : Official journal of the Metabolomic Society》2012,8(6):1130-1147
It is well established that dietary intake of n-3 fatty acids is associated with anti-inflammatory effects, and this has been linked to modulation of the oxylipin and endocannabinoid metabolomes. However, the amount of data on specific tissue effects is limited, and it is not known how inflammation affects this relation. In the present study we systematically explored the combined effects of n-3 fatty acid diets and inflammation on the in vivo endocannabinoid and oxylipin metabolomes using a multicompartment, detailed targeted lipidomics approach. Male C57BL/6 mice received diets containing 0, 1, or 3?% w/w fish oil (FO) for 6?weeks, after which 2?mg/kg LPS or saline was administered i.p. Levels of endocannabinoids/N-acylethanolamines (NAEs) and oxylipins, covering n-3 and n-6 fatty acid derived compounds, were determined in plasma, liver, ileum and adipose tissue using LC?CMS/MS. FO generally increased ??n-3?? NAEs and oxylipins at the expense of compounds derived from other fatty acids, affecting all branches of the oxylipin metabolome. LPS generally increased levels of endocannabinoids/NAEs and oxylipins, with opposing effects across plasma and tissues. Multivariate data analysis revealed that separation between diet groups in the saline treated groups was primarily explained by decreases in other than n-3 derived compounds. In the LPS treated groups, the separation was primarily explained by increases in n-3 derived compounds. In conclusion, FO caused marked changes in the n-3 to n-6 balance of the endocannabinoid and oxylipin metabolomes, with specific effects depending on inflammatory status. 相似文献