Saint-Henri, Canada
Saint-Henri, Canada
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Ducroq J.,PhysioStim | Moha Ou Maati H.,PhysioStim | Moha Ou Maati H.,University of Poitiers | Guilbot S.,PhysioStim | And 7 more authors.
British Journal of Pharmacology | Year: 2010

Introduction: Doxorubicin, an anthracycline widely used in the treatment of a broad range of tumours, causes acute QT prolongation. Dexrazoxane has been shown to prevent the QT prolongation induced by another anthracycline, epirubicin, but has not yet been reported to prevent that induced by doxorubicin. Thus, the present study was designed to test whether the acute QT effects induced by doxorubicin could be blocked by dexrazoxane and to explore the mechanism. Results were compared with those obtained with a reference human ether-a-go-go (hERG) channel blocker, moxifloxacin. Methods: The effects of moxifloxacin (100 μM) and doxorubicin (30 μM), with or without dexrazoxane (from 3 to 30 μM), have been evaluated on the QTc interval in guinea-pig isolated hearts and on IKr (rapid component of the delayed rectifier current) and IKs (slow component of the delayed rectifier current) currents stably expressed in human embryonic kidney 293 cells. Results: Moxifloxacin (100 μM), a potent hERG blocker, prolonged QTc by 22%, and this effect was not prevented by dexrazoxane. Doxorubicin (30 μM) also prolonged QTc by 13%, did not significantly block hERG channels and specifically inhibited IKs (IC50: 4.78 μM). Dexrazoxane significantly reduced the doxorubicin-induced QTc prolongation and prevented doxorubicin-induced inhibition of IKs. Conclusion and implications: Doxorubicin acutely prolonged the QT interval in guinea-pig heart by selective IKs blockade. This effect was prevented by dexrazoxane. This result is important because it illustrates the danger of neglecting IKs in favour of hERG screening alone, for early preclinical testing for possible induction of torsade de pointes. © 2009 The British Pharmacological Society.

Hupertan V.,Hopital Bichat | Neuzillet Y.,Hopital Foch | Neuzillet Y.,University of Versailles | Stucker O.,CEROM | And 4 more authors.
International Journal of Andrology | Year: 2012

Purines and more specifically adenosine monophosphate (AMP) and adenosine triphosphate (ATP) have a strong relaxant effect on smooth muscle cells of the dog, rabbit and human corpus cavernosum, to approximately the same degree as nitric oxide (NO). However, purines are considered as modulators of erectile function rather than key mediators. This suggests that the use of purines combined with NO donors could be effective to treat some specific erectile disorders. The relaxation induced by the combination of l-arginine (Arg), a natural substrate for NO synthase, was assessed with a purine-nucleotide (AMP, ATP) on a rabbit corpus cavernosum model, to determine if these substances could potentiate each other's effect. When a pre-contraction was induced by phenylephrine, AMP alone induced a 43% CC relaxation rate and ATP alone a 26% rate. The relaxation rate induced by Arg was lower in comparison (8% at 5.10-4m vs. 25% at AMP 5.10-4m and 15% at ATP 5.10-4m). NO synthase inhibitor n-nitro-l-arginine did not modify the relaxing effect provoked by AMP suggesting that the mechanism of action of this nucleotide does not involve the NO pathway. The combination of Arg at 5.10-4m with either AMP or ATP at different doses ranging from 5.10-4 to 10-3m significantly enhanced the relaxing response reaching rates of 62 and 80% respectively, leading to a synergistic effect. The present data indicate that a 'NO donor' combined with an 'adenosine donor' could be an effective therapeutic approach. © 2012 The Authors. International Journal of Andrology © 2012 European Academy of Andrology.

Choo T.M.,Agriculture and Agri Food Canada | Martin R.A.,Agriculture and Agri Food Canada | Xue A.,Agriculture and Agri Food Canada | MacDonald D.,Dalhousie University | And 4 more authors.
Canadian Journal of Plant Science | Year: 2014

AAC Mirabel is a six-row spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada. It has high grain yield and moderate resistance to barley yellow dwarf virus, powdery mildew, leaf rust, and loose smuts. AAC Mirabel performs well across Eastern Canada.

Aubin M.-P.,University of Sainte-Anne | Seguin P.,McGill University | Vanasse A.,Laval University | Lalonde O.,CEROM | And 3 more authors.
Agronomy Journal | Year: 2016

Industrial hemp (Cannabis sativa L.) is a multipurpose crop for which there is growing interest in Canada. Th ere is, however, currently limited information on the adaptation and production potential of government approved cultivars in eastern Canada. Eleven cultivars were evaluated in terms of biomass and seed yields and composition, when grown in seven contrasted environments in the province of Québec. Dry matter yields varied considerably across cultivars and environments, ranging between 172 and 8837 kg ha–1 (average of 3226 kg ha–1) for biomass, and between 47 and 3781 kg ha–1 (average of 1315 kg ha–1) for seeds. Despite the presence of cultivar × environment interactions for both biomass and seed yields, the cultivars Anka, Ferimon, and Jutta consistently produced high yields across environments. Averaged across environments, these cultivars respectively had biomass and seed yields of 4591 and 1397, 5827, and 1878, and 4096 and 1408 kg DM ha–1. Limited variation was observed among cultivars in terms of composition. Cellulose was the largest biomass constituent (average of 562 g kg–1 DM across cultivars and environments), followed by hemicellulose and lignin (averages of 123 and 93 g kg–1 DM, respectively), while seed crude protein (CP) and oil (ether extract) concentrations averaged 237 and 288 g kg–1 DM, respectively. Considerable variation in yield potential and adaptation were observed among the cultivars of industrial hemp evaluated in the province of Québec; while biomass yields were moderate, the seed yield potential appears to be high locally compared to western Canada. © 2016 by the American Society of Agronomy

Huynh T.T.,Laval University | Bastien M.,Laval University | Iquira E.,Laval University | Turcotte P.,CEROM | Belzile F.,Laval University
Crop Science | Year: 2010

White mold caused by Sclerotinia sclerotiorum (Lib.) de Bary can be an important cause of yield loss in soybean. Only partial resistance to this disease has been found to date, and little is known about the loci contributing to this resistance. The objectives of this study were to identify quantitative trait loci (QTL) associated with partial resistance to white mold progression on the main stem. One hundred eighty F4-derived lines from a cross between a partially resistant cultivar, Maple Donovan, and a susceptible cultivar, OAC Bayfield, were tested for resistance to white mold under field conditions with (2003 and 2004) or without irrigation (2005 and 2006). The resistance of the lines was assessed by measuring the length of lesions 7 d after inoculation with a mycelial suspension. These lines were genotyped with 128 simple sequence repeat markers, and three QTLs associated with lesion length were detected consistently (in at least three of the four trials). Two of the QTLs were located on LG C2 (chromosome 6) and the third was on LGI (chromosome 20). In these genomic regions, the favorable alleles came from Maple Donovan and contributed to a decrease in lesion length. Together, they accounted for 30.7 to 50.9% of lesion length variation across year trials. Selective phenotyping of 26 lines carrying contrasting alleles at these QTLs in four additional environments resulted in significant phenotypic contrasts between the two genotypic classes. © Crop Science Society of America.

Jego G.,Agriculture and Agri Food Canada | Pattey E.,Agriculture and Agri Food Canada | Bourgeois G.,Agriculture and Agri Food Canada | Morrison M.J.,Agriculture and Agri Food Canada | And 3 more authors.
Field Crops Research | Year: 2010

Crop modelling at a regional scale is often limited by the availability of input data. Soil databases can be an efficient way to provide spatial information regarding soil properties, and remote sensing has proved to be a valuable source of information of management practices through assimilation of variable, like leaf area index (LAI), in crop model. However, the large numbers of cultivars from seed companies used at the regional scale remain an important concern for regional crop modelling. The aim of this study is to test whether we can limit calibration to only one cultivar per crop for modelling LAI, biomass and yield dynamics in the Mixedwood Plains ecozone, which extends over 3° of latitude and 10° of longitude in Eastern Canada. The ability to use the new regionally adapted soybean cultivar (CanSoyEst) and spring wheat cultivar (CanBleEst) to predict LAI, biomass, and yield in the studied area was evaluated using data from several sites distributed between Southwestern Quebec and Southern Ontario. The model used is STICS, a generic open code crop model, which offers easy access to cultivar parameters and the ability to assimilate LAI from remote sensing to derive input data for regional scale studies. The CanBleEst cultivar provided good estimates of biomass and yield, with a root mean square error (RMSE) ranging between 10% and 20%. More scatter was observed for LAI estimates with a RMSE ranging from 21% to 25% depending on the sites. For the CanSoyEst cultivar, the predicted biomass had a RMSE ranging from 23% to 27% and the RMSE was about 26% for yield predictions whereas the predicted LAI showed more scatter (28%≤RMSE≤38%). A higher exposure to water stress and leaf shedding during senescence may explain why soybean output variables were predicted with more scatter. This work demonstrates that one cultivar per crop (i.e., soybean and spring wheat) provides enough accuracy to predict LAI, biomass and yield over the entire region. It provides a new soybean cultivar parameterization adapted to a short growing season and the first calibration and evaluation of a spring wheat cultivar in the STICS crop model. These contributions open new opportunities for using STICS in Northern climates characterized by short growing seasons. It also offers a foundation for crop modelling and prediction at regional scale in Eastern Canada. © 2010.

Stucker O.,CEROM | Pons C.,CEROM | Neuzillet Y.,University of Versailles | Laemmel E.,University Paris Diderot | Lebret T.,University of Versailles
Sexual Medicine | Year: 2014

Introduction: Sexual dysfunction is significantly more prevalent in women than in men. However, to date, no satisfactory oral treatment is yet available. Aim: The aim of this study was to study the effects of adenosine monophosphate (AMP) alone or its combination with L-Arginine on the relaxation of the female rabbit corpus cavernosum. Methods: Cylinder strips from the corporal body of the excised clitoris from female New Zealand White rabbits were incubated in Krebs solution. Phenylephrine (PE) precontraction was achieved, then the drugs AMP and L-Arginine were administered either independently or in sequential combinations to the strips under precontracted conditions. Main Outcome Measures: Contraction percentages were compared. Results: When precontraction was induced by PE 8μM or 20μM, AMP was shown to induce relaxation up to 25% in a dose-dependent manner. The relaxation induced by L-Arginine reached 15.6% at 5.10-4M vs. 16.5% at AMP 5.10-4M under the same experimental conditions. Nitric oxide (NO) synthase inhibitor N-nitro-L-arginine strongly inhibited the relaxing effect provoked by AMP, suggesting that the action mechanism of this nucleotide is related to the NO pathway. The combination of L-Arginine at 5.10-4M with AMP at different doses ranging from 5.10-4M to 10-3M significantly amplified the relaxing response up to 40.7% and 58%, respectively. Conclusions: Our results demonstrate that AMP induces a relaxing effect on the female rabbit corpora. They also show that L-Arginine and AMP can potentiate each other and that a synergistic effect can be obtained by their combined use. Because only slight differences exist between both sexes in response to NO donors and/or nucleotide purines or in their use together, it is very likely that close biochemical mechanisms, although not to the same degree and not quite similar, are involved in the engorgement of the penis and the clitoris of New Zealand White rabbits. Stücker O, Pons C, Neuzillet Y, Laemmel E, and Lebret T. Original research-sexual medicine: Effects of adenosine monophosphate used in combination with L-Arginine on female rabbit corpus cavernosum tissue. Sex Med 2014;2:1-7. © 2014 The Authors. Sexual Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Sexual Medicine.

Choo T.M.,Agriculture and Agri Food Canada | Ter Beek S.M.,Agriculture and Agri Food Canada | Martin R.A.,Agriculture and Agri Food Canada | Macdonald D.,Dalhousie University | And 6 more authors.
Canadian Journal of Plant Science | Year: 2015

AAC Starbuck is a two-row, spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada. It has high yield, high test weight, high seed weight, and it accumulates low concentrations of deoxynivalenol in response to Fusarium head blight infection. AAC Starbuck performs well in Quebec and the Maritimes. © 2015(Publisher Name) All Rights Reserved.

Choo T.M.,Agriculture and Agri Food Canada | Martin R.A.,Agriculture and Agri Food Canada | Terbeek S.M.,Agriculture and Agri Food Canada | Macdonald D.,Dalhousie University | And 5 more authors.
Canadian Journal of Plant Science | Year: 2015

AC Purpose is a two-row spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada. It has high grain yield, very high seed weight, and resistance to powdery mildew and leaf rust. AAC Purpose performs well in the Maritimes and Quebec. © 2015(Publisher Name). All Rights Reserved.

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