24 research outputs found

    Changes in circulating microRNA levels can be identified as early as day 8 of pregnancy in cattle

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    <div><p>Poor reproductive performance remains a major issue in the dairy industry, with low conception rates having a significant impact on milk production through extended calving intervals. A major limiting factor is the lack of reliable methods for early pregnancy diagnosis. Identification of animals within a herd that fail to conceive within 3 weeks after insemination would allow early re-insemination and shorten calving intervals. In a previous study, we found an increase in plasma miR-26a levels in Day 16-pregnant relative to non-pregnant heifers, however changes in miRNA levels that early during pregnancy were very small which likely prevented the identification of robust biomarkers. In this study, we extended our analyses to a wider interval during pregnancy (Days 8 to 60, n = 11 heifers) with the rationale that this may facilitate the identification of additional early pregnancy miRNA biomarkers. Using small RNA sequencing we identified a total of 77 miRNAs that were differentially expressed on Day 60 relative to Day 0 of pregnancy. We selected 14 miRNAs for validation by RT-qPCR and confirmed significant differences in the expression of let-7f, let-7c, miR-30c, miR-101, miR-26a, miR-205 and miR-143 between Days 0 and 60. RT-qPCR profiling throughout Days 0, 8, 16 and 60 of pregnancy showed a distinct increase in circulating levels of miR-26a (3.1-fold, P = 0.046) as early as Day 8 of pregnancy. In summary, in contrast to earlier stages of pregnancy (≤ Day 24), marked differences in the levels of multiple miRNAs can be detected in circulation by Day 60 in cattle. Retrospective analyses showed miR-26a levels to be increased in circulation as early as Day 8, sooner than previously reported in any species, suggesting a biological role for this miRNA in the very early events of pregnancy.</p></div

    Role of the Lateral Paragigantocellular Nucleus in the Network of Paradoxical (REM) Sleep: An Electrophysiological and Anatomical Study in the Rat

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    The lateral paragigantocellular nucleus (LPGi) is located in the ventrolateral medulla and is known as a sympathoexcitatory area involved in the control of blood pressure. In recent experiments, we showed that the LPGi contains a large number of neurons activated during PS hypersomnia following a selective deprivation. Among these neurons, more than two-thirds are GABAergic and more than one fourth send efferent fibers to the wake-active locus coeruleus nucleus. To get more insight into the role of the LPGi in PS regulation, we combined an electrophysiological and anatomical approach in the rat, using extracellular recordings in the head-restrained model and injections of tracers followed by the immunohistochemical detection of Fos in control, PS-deprived and PS-recovery animals. With the head-restrained preparation, we showed that the LPGi contains neurons specifically active during PS (PS-On neurons), neurons inactive during PS (PS-Off neurons) and neurons indifferent to the sleep-waking cycle. After injection of CTb in the facial nucleus, the neurons of which are hyperpolarized during PS, the largest population of Fos/CTb neurons visualized in the medulla in the PS-recovery condition was observed in the LPGi. After injection of CTb in the LPGi itself and PS-recovery, the nucleus containing the highest number of Fos/CTb neurons, moreover bilaterally, was the sublaterodorsal nucleus (SLD). The SLD is known as the pontine executive PS area and triggers PS through glutamatergic neurons. We propose that, during PS, the LPGi is strongly excited by the SLD and hyperpolarizes the motoneurons of the facial nucleus in addition to local and locus coeruleus PS-Off neurons, and by this means contributes to PS genesis

    La nutrition azotée influence l'ingestion chez la vache laitière

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    National audienceAn increase in protein content of dairy cow diets is often associated with an increased feed intake, however the magnitude of these answers and the mechanisms involved are still not well understood. This review characterizes the effects of nitrogen and protein content of the diet on feed intake in dairy cows and discusses the various hypotheses concerning their mechanisms. The supply of degradable nitrogen to the microbial population and the availability of protein for milk synthesis affects dry matter intake. These effects can be quantitatively important and generally increase with time. If the role of degradable nitrogen on microbial activity explains largely the feed intake increase, the action of proteins on the regulation of intake is less easily explained and could be multi-factorial. Similar to monogastric animals, possible modifications of the amino acid balance could also modify the control of feeding behaviour and explain the short-term intake effects. However, the increase in time of the feed intake responses to proteins militates more for indirect action via, for example the energy demand or the mobilization of the reserves, than for direct protein action on feed intake control. The response law to protein content and a better understanding of the mechanisms involved could be helpful in incorporating the effects of protein nutrition into the models of feed intake prediction.L’augmentation des teneurs en protéines des régimes est souvent associée à une augmentation de l’ingestion chez les vaches laitières, mais l’amplitude de ces réponses et les mécanismes sont encore mal connus. Cet article caractérise les effets des teneurs en azote et en protéines des régimes sur l’ingestion des aliments par les vaches laitières et discute les différentes hypothèses concernant les mécanismes. La fourniture en azote dégradable aux microbes du rumen et la disponibilité en protéines pour la synthèse du lait sont capables de stimuler l’ingestion. Ces effets peuvent être quantitativement importants et le plus souvent augmentent au cours du temps. Si le rôle de l’azote dégradable sur l’activité microbienne dans le rumen permet de bien comprendre l’augmentation des quantités ingérées, l’action des protéines sur la régulation de l’ingestion est moins facile à expliquer et pourrait être multifactorielle. Comme chez les monogastriques, les modifications possibles d’équilibre des acides aminés pourraient également modifier le contrôle de la prise alimentaire et expliquer des effets à court terme sur l’ingestion. Cependant, l’augmentation de l’effet des protéines sur l’ingestion au cours du temps milite plus pour une action indirecte, via la demande d’énergie ou la mobilisation des réserves par exemple, que pour une action directe des protéines sur le contrôle de la prise alimentaire. Ces hypothèses pourraient permettre d’intégrer les effets de l’alimentation protéique dans les modèles de prévision des quantités ingérées

    Nutritional stimulation of cholecystokinin receptors inhibits inflammation via the vagus nerve

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    The immune system in vertebrates senses exogenous and endogenous danger signals by way of complex cellular and humoral processes, and responds with an inflammatory reaction to combat putative attacks. A strong protective immunity is imperative to prevent invasion of pathogens; however, equivalent responses to commensal flora and dietary components in the intestine have to be avoided. The autonomic nervous system plays an important role in sensing luminal contents in the gut by way of hard-wired connections and chemical messengers, such as cholecystokinin (CCK). Here, we report that ingestion of dietary fat stimulates CCK receptors, and leads to attenuation of the inflammatory response by way of the efferent vagus nerve and nicotinic receptors. Vagotomy and administration of antagonists for CCK and nicotinic receptors significantly blunted the inhibitory effect of high-fat enteral nutrition on hemorrhagic shock-induced tumor necrosis factor-α and interleukin-6 release (P < 0.05). Furthermore, the protective effect of high-fat enteral nutrition on inflammation-induced intestinal permeability was abrogated by vagotomy and administration of antagonists for CCK and nicotinic receptors. These data reveal a novel neuroimmunologic pathway, controlled by nutrition, that may help to explain the intestinal hyporesponsiveness to dietary antigens, and shed new light on the functionality of nutrition

    Preoperative radiographic valgus alignment predicts the extent of lateral soft tissue release and need for constraint in valgus total knee arthroplasty

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    Background: In total knee arthroplasty (TKA) for valgus knees, the decision to use a constrained implant is often made intraoperatively depending on the extent of soft tissue releases performed and residual soft tissue imbalance. The purpose of this study is to determine if preoperative radiographic criteria of valgus knees can predict the extent of soft tissue releases required and the level of constraint needed to balance the knee during TKA. Methods: A single surgeon's 807 consecutive TKA standing hip-knee-ankle radiographs from 2007-2012 were analyzed. One hundred eighty-seven valgus knees were identified and annotated. Statistical univariate and multivariate analyses were performed for both outcomes, lateral release and articulation, to assess the association with risk factors of gender, age, and preoperative radiographic markers of valgus deformity. A P-value .05). A preoperative anatomic tibiofemoral valgus angle of >16.8° was associated with the use of a constrained articulation during surgery. Conclusions: Our data demonstrate that preoperative radiographic characteristics of the valgus knee can be utilized to predict the extent of lateral soft tissue release and whether a constrained articulation will be required in TKA. This will provide surgeons with useful information to offer accurate preoperative counseling to patients and to ensure that the appropriate prosthetic parts are available during surgery. Keywords: Total knee arthroplasty, Valgus, Constrained, Stabilized, Releas
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