23 research outputs found
RĂŽles des aquaporines dans le cerveau
Il y a maintenant plus dâune dizaine dâannĂ©es que lâaquaporine 1 (AQP1) a Ă©tĂ© mise en Ă©vidence et clonĂ©e Ă partir des globules rouges. Cette dĂ©couverte majeure pour le monde du vivant a Ă©tĂ© rĂ©compensĂ©e en 2003 par le Prix Nobel de Chimie dĂ©cernĂ© au Professeur Peter Agre. Les aquaporines (AQP) sont des canaux Ă eau. Cette famille de protĂ©ines est composĂ©e actuellement de onze sous-types diffĂ©rents exprimĂ©s chez les mammifĂšres. Les trois AQP principales caractĂ©risĂ©es dans le cerveau des mammifĂšres sont lâAQP1, lâAQP4 et lâAQP9. Les travaux rĂ©cents montrent que ces canaux sont impliquĂ©s dans diffĂ©rentes fonctions physiologiques. LâAQP1 serait importante dans la formation du liquide cĂ©phalorachidien, tandis que lâAQP4 aurait un rĂŽle dans lâhomĂ©ostasie de lâeau et de la pression osmotique du tissu nerveux. LâAQP9 serait impliquĂ©e dans le mĂ©tabolisme Ă©nergĂ©tique. En condition physiologique, le niveau dâexpression de ces AQP est finement rĂ©gulĂ©. Dans diffĂ©rentes maladies du systĂšme nerveux, le niveau dâexpression de ces canaux est modifiĂ©, ce qui peut avoir des consĂ©quences sur la formation de lâoedĂšme cĂ©rĂ©bral en modifiant la permĂ©abilitĂ© Ă lâeau. Actuellement, le rĂŽle de chacune de ces AQP dans ce phĂ©nomĂšne nâest pas encore compris. LâAQP4 semble avoir un rĂŽle trĂšs important dans le dĂ©veloppement de lâoedĂšme aprĂšs un traumatisme crĂąnien, une lĂ©sion ou un accident vasculaire cĂ©rĂ©bral. Une meilleure comprĂ©hension des mĂ©canismes de rĂ©gulation des AQP permettra dâenvisager de nouvelles stratĂ©gies thĂ©rapeutiques pour prĂ©venir la formation de lâoedĂšme cĂ©rĂ©bral. La dĂ©couverte rĂ©cente de lâAQP9 dans les neurones catĂ©cholaminergiques a modifiĂ© la vision du rĂŽle des AQP dans le systĂšme nerveux, avec une implication possible de cette derniĂšre dans le mĂ©tabolisme Ă©nergĂ©tique cĂ©rĂ©bral.It is now over 10 years ago that aquaporin 1 (AQP1) was discovered and cloned from the red blood cells, and in 2003 the Nobel price in Chemistry was awarded to Pr. Peter Agre for his work on AQPs, highlighting the importance of these proteins in life sciences. AQPs are water channels. To date this protein family is composed of 11 sub-types in mammalians. Three main AQPs described in the mammalian brain are AQP1, AQP4 and AQP9. Several recent studies have shown that these channels are implicated in numerous physiological functions. AQP1 has a role in cerebrospinal fluid formation, whereas AQP4 is involved in water homeostasis and extracellular osmotic pressure in brain parenchyma. AQP4 seems also to have an important function in oedema formation after brain trauma or brain ischemia. AQP9 is implicated in brain energy metabolism. The level of expression of each AQP is highly regulated. After a trauma or an ischemia perturbation of the central nervous system, the level of expression of each AQP is differentially modified, resulting in facilitating oedema formation. At present, the exact role of each AQP is not yet determined. A better understanding of the mechanisms of AQP regulation should permit the development of new pharmacological strategies to prevent oedema formation. AQP9 has been recently specifically detected in the catecholaminergic neurons of the brain. This new result strengthens the hypothesis that the AQPs are not only water channels, but that some AQPs may play a role in energy metabolism as metabolite channels
Classification of pig calls produced from birth to slaughter according to their emotional valence and context of production
Vocal expression of emotions has been observed across species and could provide a non-invasive and reliable means to assess animal emotions. We investigated if pig vocal indicators of emotions revealed in previous studies are valid across call types and contexts, and could potentially be used to develop an automated emotion monitoring tool. We performed an analysis of an extensive and unique dataset of low (LF) and high frequency (HF) calls emitted by pigs across numerous commercial contexts from birth to slaughter (7414 calls from 411 pigs). Our results revealed that the valence attributed to the contexts of production (positive versus negative) affected all investigated parameters in both LF and HF. Similarly, the context category affected all parameters. We then tested two different automated methods for call classification; a neural network revealed much higher classification accuracy compared to a permuted discriminant function analysis (pDFA), both for the valence (neural network: 91.5%; pDFA analysis weighted average across LF and HF (cross-classified): 61.7% with a chance level at 50.5%) and context (neural network: 81.5%; pDFA analysis weighted average across LF and HF (cross-classified): 19.4% with a chance level at 14.3%). These results suggest that an automated recognition system can be developed to monitor pig welfare on-farm.publishedVersio
Cadmium accumulation and interactions with zinc, copper, and manganese, analysed by ICP-MS in a long-term Caco-2 TC7 cell model
The influence of long-term exposure to cadmium (Cd) on essential minerals was investigated using a Caco-2
TC7 cells and a multi-analytical tool: microwave digestion and inductively coupled plasma mass spectrometry.
Intracellular levels, effects on cadmium accumulation, distribution, and reference concentration
ranges of the following elements were determined: Na, Mg, Ca, Cr, Fe, Mn, Co, Ni, Cu, Zn, Mo, and Cd.
Results showed that Caco-2 TC7 cells incubated long-term with cadmium concentrations ranging from 0 to
10 lmol Cd/l for 5 weeks exhibited a significant increase in cadmium accumulation. Furthermore, this
accumulation was more marked in cells exposed long-term to cadmium compared with controls, and that
this exposure resulted in a significant accumulation of copper and zinc but not of the other elements
measured. Interactions of Cd with three elements: zinc, copper, and manganese were particularly studied.
Exposed to 30 lmol/l of the element, manganese showed the highest inhibition and copper the lowest on
cadmium intracellular accumulation but Zn, Cu, and Mn behave differently in terms of their mutual
competition with Cd. Indeed, increasing cadmium in the culture medium resulted in a gradual and significant
increase in the accumulation of zinc. There was a significant decrease in manganese from 5 lmol
Cd/l exposure, and no variation was observed with copper.
Abbreviation: AAS â Atomic absorption spectrometry; CRMâ Certified reference material; PBS â Phosphate
buffered saline without calcium and magnesium; DMEM â Dubelccoâs modified Eagleâs medium
A Deletion in Exon 9 of the LIPH Gene Is Responsible for the Rex Hair Coat Phenotype in Rabbits (Oryctolagus cuniculus)
The fur of common rabbits is constituted of 3 types of hair differing in length and diameter while that of rex animals is essentially made up of amazingly soft down-hair. Rex short hair coat phenotypes in rabbits were shown to be controlled by three distinct loci. We focused on the âr1â mutation which segregates at a simple autosomal-recessive locus in our rabbit strains. A positional candidate gene approach was used to identify the rex gene and the corresponding mutation. The gene was primo-localized within a 40 cM region on rabbit chromosome 14 by genome scanning families of 187 rabbits in an experimental mating scheme. Then, fine mapping refined the region to 0.5 cM (Zâ=â78) by genotyping an additional 359 offspring for 94 microsatellites present or newly generated within the first defined interval. Comparative mapping pointed out a candidate gene in this 700 kb region, namely LIPH (Lipase Member H). In humans, several mutations in this major gene cause alopecia, hair loss phenotypes. The rabbit gene structure was established and a deletion of a single nucleotide was found in LIPH exon 9 of rex rabbits (1362delA). This mutation results in a frameshift and introduces a premature stop codon potentially shortening the protein by 19 amino acids. The association between this deletion and the rex phenotype was complete, as determined by its presence in our rabbit families and among a panel of 60 rex and its absence in all 60 non-rex rabbits. This strongly suggests that this deletion, in a homozygous state, is responsible for the rex phenotype in rabbits
A Deletion in Exon 9 of the LIPH Gene Is Responsible for the Rex Hair Coat Phenotype in Rabbits (Oryctolagus cuniculus)
The fur of common rabbits is constituted of 3 types of hair differing in length and diameter while that of rex animals is essentially made up of amazingly soft down-hair. Rex short hair coat phenotypes in rabbits were shown to be controlled by three distinct loci. We focused on the âr1â mutation which segregates at a simple autosomal-recessive locus in our rabbit strains. A positional candidate gene approach was used to identify the rex gene and the corresponding mutation. The gene was primo-localized within a 40 cM region on rabbit chromosome 14 by genome scanning families of 187 rabbits in an experimental mating scheme. Then, fine mapping refined the region to 0.5 cM (Zâ=â78) by genotyping an additional 359 offspring for 94 microsatellites present or newly generated within the first defined interval. Comparative mapping pointed out a candidate gene in this 700 kb region, namely LIPH (Lipase Member H). In humans, several mutations in this major gene cause alopecia, hair loss phenotypes. The rabbit gene structure was established and a deletion of a single nucleotide was found in LIPH exon 9 of rex rabbits (1362delA). This mutation results in a frameshift and introduces a premature stop codon potentially shortening the protein by 19 amino acids. The association between this deletion and the rex phenotype was complete, as determined by its presence in our rabbit families and among a panel of 60 rex and its absence in all 60 non-rex rabbits. This strongly suggests that this deletion, in a homozygous state, is responsible for the rex phenotype in rabbits
The significance of viscoelastic parameters in experimental Acute Respiratory Distress Syndrome. A lung CT study.
International audienc
Reliability of the nitrogen washout-washin technique to assess end-expiratory lung volume at variable PEEP and tidal volumes
International audienc
Effects of PEEP and tidal volume on the reliability of end-expiratory volume measurement with the nitrogen washout/washin technique
International audienc
Assessment of trending ability of the nitrogen washout-washin technique to detect change in end-expiratory lung volume
International audienc
Viscoelastic parameters of the respiratory system and tidal recruitment. A lung CT investigation in experimental Acute Respiratory Distress Syndrome.
International audienc