86 research outputs found
Deregulated lipid sensing by intestinal CD36 in diet-induced hyperinsulinemic obese mouse model
The metabolic syndrome (MetS) greatly increases risk of cardiovascular disease and diabetes and is generally associated with abnormally elevated postprandial triglyceride levels. We evaluated intestinal synthesis of triglyceride-rich lipoproteins (TRL) in a mouse model of the MetS obtained by feeding a palm oil-rich high fat diet (HFD). By contrast to control mice, MetS mice secreted two populations of TRL. If the smaller size population represented 44% of total particles in the beginning of intestinal lipid absorption in MetS mice, it accounted for only 17% after 4 h due to the secretion of larger size TRL. The MetS mice displayed accentuated postprandial hypertriglyceridemia up to 3 h due to a defective TRL clearance. These alterations reflected a delay in lipid induction of genes for key proteins of TRL formation (MTP, L-FABP) and blood clearance (ApoC2). These abnormalities associated with blunted lipid sensing by CD36, which is normally required to optimize jejunal formation of large TRL. In MetS mice CD36 was not downregulated by lipid in contrast to control mice. Treatment of controls with the proteosomal inhibitor MG132, which prevented CD36 downregulation, resulted in blunted lipid-induction of MTP, L-FABP and ApoC2 gene expression, as in MetS mice. Absence of CD36 sensing was due to the hyperinsulinemia in MetS mice. Acute insulin treatment of controls before lipid administration abolished CD36 downregulation, lipid-induction of TRL genes and reduced postprandial triglycerides (TG), while streptozotocin-treatment of MetS mice restored lipid-induced CD36 degradation and TG secretion. In vitro, insulin treatment abolished CD36-mediated up-regulation of MTP in Caco-2 cells. In conclusion, HFD treatment impairs TRL formation in early stage of lipid absorption via insulin-mediated inhibition of CD36 lipid sensing. This impairment results in production of smaller TRL that are cleared slowly from the circulation, which might contribute to the reported association of CD36 variants with MetS risk
Zygote arrest 1 gene in pig, cattle and human: evidence of different transcript variants in male and female germ cells
BACKGROUND: Zygote arrest 1 (ZAR1) is one of the few known oocyte-specific maternal-effect genes essential for the beginning of embryo development discovered in mice. This gene is evolutionary conserved in vertebrates and ZAR1 protein is characterized by the presence of atypical plant homeobox zing finger domain, suggesting its role in transcription regulation. This work was aimed at the study of this gene, which could be one of the key regulators of successful preimplantation development of domestic animals, in pig and cattle, as compared with human. METHODS: Screenings of somatic cell hybrid panels and in silico research were performed to characterize ZAR1 chromosome localization and sequences. Rapid amplification of cDNA ends was used to obtain full-length cDNAs. Spatio-temporal mRNA expression patterns were studied using Northern blot, reverse transcription coupled to polymerase chain reaction and in situ hybridization. RESULTS: We demonstrated that ZAR1 is a single copy gene, positioned on chromosome 8 in pig and 6 in cattle, and several variants of correspondent cDNA were cloned from oocytes. Sequence analysis of ZAR1 cDNAs evidenced numerous short inverted repeats within the coding sequences and putative Pumilio-binding and embryo-deadenylation elements within the 3'-untranslated regions, indicating the potential regulation ways. We showed that ZAR1 expressed exclusively in oocytes in pig ovary, persisted during first cleavages in embryos developed in vivo and declined sharply in morulae and blastocysts. ZAR1 mRNA was also detected in testis, and, at lower level, in hypothalamus and pituitary in both species. For the first time, ZAR1 was localized in testicular germ cells, notably in round spermatids. In addition, in pig, cattle and human only shorter ZAR1 transcript variants resulting from alternative splicing were found in testis as compared to oocyte. CONCLUSION: Our data suggest that in addition to its role in early embryo development highlighted by expression pattern of full-length transcript in oocytes and early embryos, ZAR1 could also be implicated in the regulation of meiosis and post meiotic differentiation of male and female germ cells through expression of shorter splicing variants. Species conservation of ZAR1 expression and regulation underlines the central role of this gene in early reproductive processes
An mTRAN-mRNA interaction mediates mitochondrial translation initiation in plants
Plant mitochondria represent the largest group of respiring organelles on the planet. Plant mitochondrial messenger RNAs (mRNAs) lack Shine-Dalgarno-like ribosome-binding sites, so it is unknown how plant mitoribosomes recognize mRNA. We show that âmitochondrial translation factorsâ mTRAN1 and mTRAN2 are land plantâspecific proteins, required for normal mitochondrial respiration chain biogenesis. Our studies suggest that mTRANs are noncanonical pentatricopeptide repeat (PPR)âlike RNA binding proteins of the mitoribosomal âsmallâ subunit. We identified conserved Adenosine (A)/Uridine (U)-rich motifs in the 5âČ regions of plant mitochondrial mRNAs. mTRAN1 binds this motif, suggesting that it is a mitoribosome homing factor to identify mRNAs. We demonstrate that mTRANs are likely required for translation of all plant mitochondrial mRNAs. Plant mitochondrial translation initiation thus appears to use a protein-mRNA interaction that is divergent from bacteria or mammalian mitochondria
Rift Valley fever vector diversity and impact of meteorological and environmental factors on Culex pipiens dynamics in the Okavango Delta, Botswana
BACKGROUND : In Northern Botswana, rural communities, livestock, wildlife and large numbers of mosquitoes
cohabitate around permanent waters of the Okavango Delta. As in other regions of sub-Saharan Africa, Rift Valley
Fever (RVF) virus is known to circulate in that area among wild and domestic animals. However, the diversity and
composition of potential RVF mosquito vectors in that area are unknown as well as the climatic and ecological
drivers susceptible to affect their population dynamics.
METHODS : Using net traps baited with carbon dioxide, monthly mosquito catches were implemented over four sites
surrounding cattle corrals at the northwestern border of the Okavango Delta between 2011 and 2012. The
collected mosquito species were identified and analysed for the presence of RVF virus by molecular methods. In
addition, a mechanistic model was developed to assess the qualitative influence of meteorological and
environmental factors such as temperature, rainfall and flooding levels, on the population dynamics of the most
abundant species detected (Culex pipiens).
RESULTS : More than 25,000 mosquitoes from 32 different species were captured with an overabundance of Cx.
pipiens (69,39 %), followed by Mansonia uniformis (20,67 %) and a very low detection of Aedes spp. (0.51 %). No RVF
virus was detected in our mosquito pooled samples. The model fitted well the Cx. pipiens catching results (Ï = 0.94,
P = 0.017). The spatial distribution of its abundance was well represented when using local rainfall and flooding
measures (Ï = 1, P = 0.083). The global population dynamics were mainly influenced by temperature, but both
rainfall and flooding presented a significant influence. The best and worst suitable periods for mosquito abundance
were around March to May and June to October, respectively.
CONCLUSIONS : Our study provides the first available data on the presence of potential RVF vectors that could
contribute to the maintenance and dissemination of RVF virus in the Okavango Delta. Our model allowed us to
understand the dynamics of Cx. pipiens, the most abundant vector identified in this area. Potential predictions of
peaks in abundance of this vector could allow the identification of the most suitable periods for disease occurrence
and provide recommendations for vectorial and disease surveillance and control strategies.Additional file 1: Serological analysis (Sampling strategy, laboratory
analysis and results).Additional file 2: Mapping flooding extent method. Figure in Additional
file 2. Maps of Modified Normalized Difference Water Index (MNDWI)
derived from MODIS imagery at different dates corresponding to the
study period.Additional file 3 Detail of the ordinary differential equation system.Funding was provided by FAO. Award Number: LoA OSRO/INT/602/USA/B1.http://www.parasitesandvectors.comam2016Zoology and Entomolog
Better cosmetic results and comparable quality of life after skin-sparing mastectomy and immediate autologous breast reconstruction compared to breast conservative treatment
«La relation de limitation et dâexception dans le français dâaujourdâhui : exceptĂ©, sauf et hormis comme pivots dâune relation algĂ©brique »
Lâanalyse des emplois prĂ©positionnels et des emplois conjonctifs dâ âexceptĂ©â, de âsaufâ et dâ âhormisâ permet dâenvisager les trois prĂ©positions/conjonctions comme le pivot dâun binĂŽme, comme la plaque tournante dâune structure bipolaire. PlacĂ©es au milieu du binĂŽme, ces prĂ©positions sont forcĂ©es par leur sĂ©mantisme originaire dĂ»ment mĂ©taphorisĂ© de jouer le rĂŽle de marqueurs dâinconsĂ©quence systĂ©matique entre lâĂ©lĂ©ment se trouvant Ă leur gauche et celui qui se trouve Ă leur droite. Lâopposition qui surgit entre les deux Ă©lĂ©ments nâest donc pas une incompatibilitĂ© naturelle, intrinsĂšque, mais extrinsĂšque, induite. Dans la plupart des cas (emplois limitatifs), cette opposition prend la forme dâun rapport entre une « classe » et le « membre (soustrait) de la classe », ou bien entre un « tout » et une « partie » ; dans dâautres (emplois exceptifs), cette opposition se manifeste au contraire comme une attaque de front portĂ©e par un « tout » Ă un autre « tout ». De plus, lâinconsĂ©quence induite mise en place par la prĂ©position/conjonction paraĂźt, en principe, tout Ă fait insurmontable. Dans lâassertion « les Ă©cureuils vivent partout, sauf en Australie » (que lâon peut expliciter par « Les Ă©cureuils vivent partout, sauf [quâils ne vivent pas] en Australie »), la prĂ©position semble en effet capable dâimpliquer le prĂ©dicat principal avec signe inverti, et de bĂątir sur une telle implication une sorte de sous Ă©noncĂ© qui, Ă la rigueur, est totalement inconsĂ©quent avec celui qui le prĂ©cĂšde (si « les Ă©cureuils ne vivent pas en Australie », le fait quâils « vivent partout » est faux). NĂ©anmoins, lâanalyse montre quâalors que certaines de ces oppositions peuvent enfin ĂȘtre dĂ©passĂ©es, dâautres ne le peuvent pas. Câest, respectivement, le cas des relations limitatives et des relations exceptives. La relation limitative, impliquant le rapport « tout » - « partie », permet de rĂ©soudre le conflit dans les termes dâune somme algĂ©brique entre deux sous Ă©noncĂ©s pourvus de diffĂ©rent poids informatif et de signe contraire. Les valeurs numĂ©riques des termes de la somme Ă©tant dĂ©sĂ©quilibrĂ©es, le rĂ©sultat est toujours autre que zĂ©ro. La relation exceptive, au contraire, qui nâimplique pas le rapport « tout » - « partie », nâest pas capable de rĂ©soudre le conflit entre deux sous Ă©noncĂ©s pourvus du mĂȘme poids informatif et en mĂȘme temps de signe contraire : les valeurs numĂ©riques des termes de la somme Ă©tant symĂ©triques et Ă©gales, le rĂ©sultat sera toujours Ă©quivalent Ă zĂ©ro
The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases
The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article
Fostering innovation: an organisational perspective
This article offers an organisational perspective on innovation in healthcare. It suggests that healthcare managers can become active, rather than passive, forces of innovation and change adoption and can create positive organisational dynamics, by successfully identifying the inhibitors and enhancers of innovation processes. Four phases of the innovation process are introduced (i.e. problem identification, idea generation, idea evaluation and implementation), and the specificities of the individual, team and organisational context are considered to overcome barriers to innovation. Finally, the article highlights the iterative nature of innovation in relation to the four phases of innovation and illustrates how ideas are transferred and transformed as they unfold across organisational levels
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