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141.
Benedicte Fustec Thipruethai Phanitchat Sirinart Aromseree Chamsai Pientong Kesorn Thaewnongiew Tipaya Ekalaksananan Dominique Cerqueira Anne Poinsignon Eric Elguero Michael J. Bangs Neal Alexander Hans J. Overgaard Vincent Corbel 《PLoS neglected tropical diseases》2021,15(5)
BackgroundAedes mosquitoes are vectors for several major arboviruses of public health concern including dengue viruses. The relationships between Aedes infestation and disease transmission are complex wherein the epidemiological dynamics can be difficult to discern because of a lack of robust and sensitive indicators for predicting transmission risk. This study investigates the use of anti-Aedes saliva antibodies as a serological biomarker for Aedes mosquito bites to assess small scale variations in adult Aedes density and dengue virus (DENV) transmission risk in northeastern Thailand. Individual characteristics, behaviors/occupation and socio-demographics, climatic and epidemiological risk factors associated with human-mosquito exposure are also addressed.MethodsThe study was conducted within a randomized clustered control trial in Roi Et and Khon Kaen provinces over a consecutive 19 months period. Thirty-six (36) clusters were selected, each of ten houses. Serological and entomological surveys were conducted in all houses every four months and monthly in three sentinel households per cluster between September 2017 and April 2019 for blood spot collections and recording concurrent immature and adult Aedes indices. Additionally, the human exposure to Aedes mosquito bites (i.e., Mosquito Exposure Index or MEI) was estimated by ELISA measuring levels of human antibody response to the specific Nterm-34 kDa salivary antigen. The relationships between the MEI, vector infestation indices (adult and immature stages) and vector DENV infection were evaluated using a two-level (house and individual levels) mixed model analysis with one-month lag autoregressive correlation.ResultsThere was a strong positive relationship between the MEI and adult Aedes (indoor and outdoor) density. Individuals from households with a medium mosquito density (mean difference: 0.091, p<0.001) and households with a high mosquito density (mean difference: 0.131, p<0.001) had higher MEI’s compared to individuals from households without Aedes. On a similar trend, individuals from households with a low, medium or high indoor Aedes densities (mean difference: 0.021, p<0.007, 0.053, p<0.0001 and 0.037, p<0.0001 for low, medium and high levels of infestation, respectively) had higher MEI than individuals from houses without indoor Aedes. The MEI was driven by individual characteristics, such as gender, age and occupation/behaviors, and varied according to climatic, seasonal factors and vector control intervention (p<0.05). Nevertheless, the study did not demonstrate a clear correlation between MEI and the presence of DENV-infected Aedes.ConclusionThis study represents an important step toward the validation of the specific IgG response to the Aedes salivary peptide Nterm-34kDa as a proxy measure for Aedes infestation levels and human-mosquito exposure risk in a dengue endemic setting. The use of the IgG response to the Nterm-34 kDa peptide as a viable diagnostic tool for estimating dengue transmission requires further investigations and validation in other geographical and transmission settings. 相似文献
142.
Virginie Grizon Marie Dominique Legoy Sylvain Lamare 《Biocatalysis and Biotransformation》2013,31(3):177-182
It has recently been demonstrated that dried cells of Saccharomyces cerevisiae were able to produce alcohols and aldehydes in a solid/gas reactor with in situ cofactor regeneration. Since diffusion of gaseous substrates may be limited by the membrane and cell wall, cell disruption by sonication was used to improve oxidoreduction with ethanol and butyraldehyde as substrates. Results showed that partial cell disruption enhances the maximum conversion yield with the best results obtained after 2 min of sonication. Beyond this time, the ADH activity decreased. Better stability was observed in the pellet obtained after centrifugation indicating the importance of cell environment for enzyme stability. Tests on purified mitochondria showed that the ADH activity in cells was mainly cytoplasmic. The addition of oxidized cofactor did not change either the activity or the stability of the catalyst in a gaseous medium. The effect of water activity was studied on material obtained after 2 min of disruption and a reduction of critical water activity needed for revealing enzymatic activity was observed. With increasing aw, the enzyme was active at aw=0.3 while a water activity of 0.4 was required before disruption. Nevertheless, the best compromise between activity and stability was obtained in both cases for a water activity of 0.57. 相似文献
143.
Christoph Engelhardt Valérie Malfroy Camine David Ingram Philippe Müllhaupt Alain Farron Dominique Pioletti 《Computer methods in biomechanics and biomedical engineering》2013,16(12):1272-1279
The estimation of muscle forces in musculoskeletal shoulder models is still controversial. Two different methods are widely used to solve the indeterminacy of the system: electromyography (EMG)-based methods and stress-based methods. The goal of this work was to evaluate the influence of these two methods on the prediction of muscle forces, glenohumeral load and joint stability after total shoulder arthroplasty. An EMG-based and a stress-based method were implemented into the same musculoskeletal shoulder model. The model replicated the glenohumeral joint after total shoulder arthroplasty. It contained the scapula, the humerus, the joint prosthesis, the rotator cuff muscles supraspinatus, subscapularis and infraspinatus and the middle, anterior and posterior deltoid muscles. A movement of abduction was simulated in the plane of the scapula. The EMG-based method replicated muscular activity of experimentally measured EMG. The stress-based method minimised a cost function based on muscle stresses. We compared muscle forces, joint reaction force, articular contact pressure and translation of the humeral head. The stress-based method predicted a lower force of the rotator cuff muscles. This was partly counter-balanced by a higher force of the middle part of the deltoid muscle. As a consequence, the stress-based method predicted a lower joint load (16% reduced) and a higher superior–inferior translation of the humeral head (increased by 1.2 mm). The EMG-based method has the advantage of replicating the observed cocontraction of stabilising muscles of the rotator cuff. This method is, however, limited to available EMG measurements. The stress-based method has thus an advantage of flexibility, but may overestimate glenohumeral subluxation. 相似文献
144.
Alexandre Terrier Marjan Sedighi-Gilani Alireza Roshan Ghias Line Aschwanden Dominique P. Pioletti 《Computer methods in biomechanics and biomedical engineering》2013,16(3):333-339
Tibial bone defect is a critical problem for revision knee arthroplasty. Instead of using metallic spacer or cement, biodegradable scaffolds could be an alternative solution. A numerical model of a revision knee arthroplasty was thus developed to estimate the mechanical resistance of the scaffold in this demanding situation. The tibia, scaffold, and prosthesis were represented by simplified parameterised geometries. The maximal gait cycle force was applied asymmetrically to simulate a critical loading. Several parameters were analysed: 1) inter-individual variability, 2) cortical bone stiffness, 3) cortical bone thickness, 4) prosthesis fixation quality, and 5) scaffold thickness. The calculated scaffold strain was compared to its experimental ultimate strain. Among the tested parameters, failure was only predicted with scaffold thickness below 5 mm. This study suggests that biodegradable bone scaffolds could be used to fill bone defects in revision knee arthroplasty, but scaffold size seems to be the limiting factor. 相似文献
145.
Stéphanie Gourdain Christian Petermann Dominique Harakat Pascale Clivio 《Nucleosides, nucleotides & nucleic acids》2013,32(7):542-546
Previously reported syntheses of the photoaffinity label 5-azido-2′-deoxyuridine are rather inefficient and involve the tedious preparation of a 5-nitro intermediate. To overcome these inconveniences, we have developed a new approach from the commercially available 5-bromo-2′-deoxyuridine nucleoside. Our synthetic route makes use of a benzylamination reduction sequence. Using this strategy, the 5-azido-2′-deoxyuridine photolabel is prepared in three steps and quantitative yields. 相似文献
146.
Guillaume E. Beranger Michael Karbiener Valentin Barquissau Didier F. Pisani Marcel Scheideler Dominique Langin Ez-Zoubir Amri 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2013,1831(5):905-914
Brown adipose tissue (BAT) has long been thought to be absent or very scarce in human adults so that its contribution to energy expenditure was not considered as relevant. The recent discovery of thermogenic BAT in human adults opened the field for innovative strategies to combat overweight/obesity and associated diseases. This energy-dissipating function of BAT is responsible for adaptive thermogenesis in response to cold stimulation. In this context, adipocytes can be converted, within white adipose tissue (WAT), into multilocular adipocytes expressing UCP1, a mitochondrial protein that plays a key role in heat production by uncoupling the activity of the respiratory chain from ATP synthesis. These adipocytes have been named “brite” or “beige” adipocytes. Whereas BAT has been studied for a long time in murine models both in vivo and in vitro, there is now a strong demand for human cellular models to validate and/or identify critical factors involved in the induction of a thermogenic program within adipocytes. In this review we will discuss the different human cellular models described in the literature and what is known regarding the regulation of their differentiation and/or activation process. In addition, the role of microRNAs as novel regulators of brown/“brite” adipocyte differentiation and conversion will be depicted. Finally, investigation of both the conversion and the metabolism of white-to-brown converted adipocytes is required for the development of therapeutic strategies targeting overweight/obesity and associated diseases. This article is part of a Special Issue entitled Brown and White Fat: From Signaling to Disease. 相似文献
147.
Global Analysis of Apicomplexan Protein S‐Acyl Transferases Reveals an Enzyme Essential for Invasion
Karine Frénal Chwen L. Tay Christina Mueller Ellen S. Bushell Yonggen Jia Arnault Graindorge Oliver Billker Julian C. Rayner Dominique Soldati‐Favre 《Traffic (Copenhagen, Denmark)》2013,14(8):895-911
The advent of techniques to study palmitoylation on a whole proteome scale has revealed that it is an important reversible modification that plays a role in regulating multiple biological processes. Palmitoylation can control the affinity of a protein for lipid membranes, which allows it to impact protein trafficking, stability, folding, signalling and interactions. The publication of the palmitome of the schizont stage of Plasmodium falciparum implicated a role for palmitoylation in host cell invasion, protein export and organelle biogenesis. However, nothing is known so far about the repertoire of protein S‐acyl transferases (PATs) that catalyse this modification in Apicomplexa. We undertook a comprehensive analysis of the repertoire of Asp‐His‐His‐Cys cysteine‐rich domain (DHHC‐CRD) PAT family in Toxoplasma gondii and Plasmodium berghei by assessing their localization and essentiality. Unlike functional redundancies reported in other eukaryotes, some apicomplexan‐specific DHHCs are essential for parasite growth, and several are targeted to organelles unique to this phylum. Of particular interest is DHHC7, which localizes to rhoptry organelles in all parasites tested, including the major human pathogen P. falciparum. TgDHHC7 interferes with the localization of the rhoptry palmitoylated protein TgARO and affects the apical positioning of the rhoptry organelles. This PAT has a major impact on T. gondii host cell invasion, but not on the parasite's ability to egress. 相似文献
148.
Jean-Luc Montillet Nathalie Leonhardt Samuel Mondy Sylvain Tranchimand Dominique Rumeau Marie Boudsocq Ana Victoria Garcia Thierry Douki Jean Bigeard Christiane Laurière Anne Chevalier Carmen Castresana Heribert Hirt 《PLoS biology》2013,11(3)
Plant stomata function in innate immunity against bacterial invasion and abscisic acid (ABA) has been suggested to regulate this process. Using genetic, biochemical, and pharmacological approaches, we demonstrate that (i) the Arabidopsis thaliana nine-specific-lipoxygenase encoding gene, LOX1, which is expressed in guard cells, is required to trigger stomatal closure in response to both bacteria and the pathogen-associated molecular pattern flagellin peptide flg22; (ii) LOX1 participates in stomatal defense; (iii) polyunsaturated fatty acids, the LOX substrates, trigger stomatal closure; (iv) the LOX products, fatty acid hydroperoxides, or reactive electrophile oxylipins induce stomatal closure; and (v) the flg22-mediated stomatal closure is conveyed by both LOX1 and the mitogen-activated protein kinases MPK3 and MPK6 and involves salicylic acid whereas the ABA-induced process depends on the protein kinases OST1, MPK9, or MPK12. Finally, we show that the oxylipin and the ABA pathways converge at the level of the anion channel SLAC1 to regulate stomatal closure. Collectively, our results demonstrate that early biotic signaling in guard cells is an ABA-independent process revealing a novel function of LOX1-dependent stomatal pathway in plant immunity. 相似文献
149.
150.
Chloe I. Bloom Christine M. Graham Matthew P. R. Berry Fotini Rozakeas Paul S. Redford Yuanyuan Wang Zhaohui Xu Katalin A. Wilkinson Robert J. Wilkinson Yvonne Kendrick Gilles Devouassoux Tristan Ferry Makoto Miyara Diane Bouvry Valeyre Dominique Guy Gorochov Derek Blankenship Mitra Saadatian Phillip Vanhems Huw Beynon Rama Vancheeswaran Melissa Wickremasinghe Damien Chaussabel Jacques Banchereau Virginia Pascual Ling-pei Ho Marc Lipman Anne O’Garra 《PloS one》2013,8(8)