Effect of Diet Supplementation with the Mycotoxin Binder Montmorillonite on the Bioavailability of Vitamins in Dairy Cows

The objective of this study was to determine the effect of the mycotoxin binder montmorillonite (MMT) supplemented in the diet of dairy cows on the bioavailability of vitamins A, D, E, B1 and B6. Six multiparous Holstein-Friesian cows were used in a crossover design with two periods. Treatments were a control diet with or without MMT. Vitamins were infused individually into the abomasum through the ruminal cannula. Blood samples were collected from the jugular vein at 0, 1, 2, 3, 4, 6, 9, 12, 24 and 48 h after the administration of each vitamin. Results showed that vitamin A reached maximal concentration (Tmax) at 5.3 h after dosing, the maximal concentration (Cmax) was 1.2 times higher than the basal concentration (Cbasal), and the area under the curve (AUC) was 739 arbitrary units. Vitamin B6 reached the Tmax at 13 h after dosing, the Cmax was 1.4 times higher than the Cbasal, and the AUC was 222 arbitrary units. No differences were observed in Cbasal, Tmax, Cmax and AUC of vitamin A and B6 between control vs. MMT-supplemented cows. Plasma concentrations of vitamins D, E and B1 had no concentration peaks, and were not affected by MMT addition. The lack of a response suggests that their plasma concentration may be tightly regulated. Results of this study do not show evidence that MMT affects the bioavailability of vitamins A and B6 in vivo.

Carbon Nanotube Electrodes for Electrochemical Detection of Dopamine

Carbon nanotubes (CNTs) are suited for neurochemistry because of their biological inertness, ability to withstand biofouling, and superior electron transport kinetics. Dopamine, the canonical monoaminergic neuromodulator, contributes to reward, cognition and attention, however, its detection in real-time is challenging due to its low basal concentration in the brain (100nM L-1). In our present work, we fabricate pyrolytic carbon electrodes and perform a CNT coating to improve the electrochemical kinetics of dopamine. Upon CNTs coating, dopamine shows a sensitivity of 9±18nA/μM for a cylindrical electrode having a mean surface diameter of 8±4μm. Increasing the scan frequency from 10-100 Hz shows that dopamine electron transfer kinetics improves; wherein dopamine is oxidized at 0.35±0.09V and reduced to -0.10±0.05V for 10 Hz. Increasing the frequency results in a shift of oxidation peak towards the anodic region, wherein dopamine oxidizes at 0.08±3V and reduces at -0.1±0.05V for 100 Hz, thus showing that dopamine redox is reversible which can be attributed to the superior electron transport kinetics of CNTs. The sensor was able to distinguish dopamine signals against other neurochemicals like serotonin and foulant 3,4-Dihydroxyphenylacetic acid (DOPAC). The minimum chemical detection that can be performed using these nanopipettes is 50±18nM L-1, which is well below the physiological concentrations of dopamine in the brain.Graphical AbstractA: Pictorial view of background-subtracted voltammetry. The waveform used was -0.4V to 1.3 V and cycled back to -0.4V at 10 Hz. B: The voltammogram was converted as a 2-D representation, into current, voltage, and repetition to understand the dopamine oxidation. C: Background subtracted voltammetry for dopamine using 100 Hz waveform. D: The 2-D representation of current, voltage, and repetition.

The Regulation of Circulating Hepatokines by Fructose Ingestion Levels in Humans

Background Fibroblast growth factor 21 (FGF21), follistatin, angiopoietin-like 4 (ANGPTL4) and growth differential factor 15 (GDF15) are regulated by the energy metabolism. Recent findings in humans demonstrate that fructose ingestion increases circulating FGF21 with increased response in conditions of insulin resistance. Objective to study the acute effect of fructose and somatostatin on circulating FGF21, follistatin, ANGPTL4 and GDF15 in humans. Methods Plasma FGF21, follistatin, ANGPTL4 and GDF15 concentrations were measured in response to oral ingestion of 75g of fructose in 10 young healthy males with and without a 15-minute infusion of somatostatin to block insulin secretion. A control infusion of somatostatin was also performed in the same subjects. Results Following fructose ingestion, plasma FGF21 peaked at 3.7-fold basal concentration (p<0.05) and increased 4.9-fold compared with basal concentration. (p<0.05) when somatostatin was infused. Plasma follistatin increased 1.8-fold after fructose ingestion (p<0.05), but this increase was blunted by concomitant somatostatin infusion. For plasma ANGPTL4 and GDF-15, no increases were obtained following fructose ingestion. Infusion of somatostatin alone slightly increased plasma FGF21 and follistatin. Conclusions Here we show in humans that 1) the fructose-induced increase in plasma FGF21 was enhanced when somatostatin was infused suggesting an inhibitory role of insulin on the fructose-induced FGF21 increase; 2) fructose ingestion also increased plasma follistatin, but somatostatin infusion had no effect on the increase; 3) fructose ingestion had no stimulating effect on ANGPTL4 and GDF15 levels demonstrating differences in the hepatokine response to fructose ingestion.

Oxidative Stress in Cardiovascular Diseases: Still a Therapeutic Target?

Cardiovascular diseases (CVD) are complex entities with heterogenous pathophysiologic mechanisms and increased oxidative stress has been viewed as one of the potential common etiologies. A fine balance between the presence of reactive oxygen species (ROS) and antioxidants is essential for the proper normal functioning of the cell. A basal concentration of ROS is indispensable for the manifestation of cellular functions, whereas excessive levels of ROS cause damage to cellular macromolecules such as DNA, lipids and proteins, eventually leading to necrosis and apoptotic cell death. CVD is the main cause of death worldwide with several conditions being affected by oxidative stress. Increased ROS lead to decreased nitric oxide availability and vasoconstriction, promoting arterial hypertension. ROS also negatively influence myocardial calcium handling, causing arrhythmia, and augment cardiac remodeling by inducing hypertrophic signaling and apoptosis. Finally, ROS have also been shown to promote atherosclerotic plaque formation. This review aims at giving an introduction into oxidative stress in CVD, with special focus on endothelial dysfunction, and then examining in detail the role of oxidative stress in the most prevalent of these diseases. Finally, potential nutraceuticals and diets that might be beneficial in diminishing the burden of oxidative stress in CVD are presented.

Upregulation of GH, but not IGF1, in the hippocampus of the lactating dam after kainic acid injury

Lactation embodies a natural model of morphological, neurochemical, and functional brain plasticity. In this reproductive stage, the hippocampus of the female is less sensitive to excitotoxins in contrast to nulliparity. Growth hormone (GH) and insulin-like growth factor 1 (IGF1) are known to be neuroprotective in several experimental models of brain lesion. Here, activation of the GH–IGF1 pituitary–brain axis following kainic acid (7.5 mg/kg i.p. KA) lesion was studied in lactating and nulliparous rats. Serum concentrations of GH and IGF1 were uncoupled in lactation. Compared to virgin rats, the basal concentration of GH increased up to 40% but IGF1 decreased 58% in dams, and only GH increased further after KA treatment. In the hippocampus, basal expression of GH mRNA was higher (2.8-fold) in lactating rats than in virgin rats. GH mRNA expression in lactating rats increased further after KA administration in the hippocampus and in the hypothalamus, in parallel to GH protein concentration in the hippocampus of KA-treated lactating rats (43% vs lactating control), as detected by Western blot and immunofluorescence. Except for the significantly lower mRNA concentration in the liver of lactating rats, IGF1 expression was not altered by the reproductive condition or by KA treatment in the hippocampus and hypothalamus. Present results indicate upregulation of GH expression in the hippocampus after an excitotoxic lesion, suggesting paracrine/autocrine actions of GH as a factor underlying neuroprotection in the brain of the lactating dam. Since no induction of IGF1 was detected, present data suggest a direct action of GH.

Monitoring of Physiological Changes of Uric Acid Concentration in the Blood of Snakes

The evaluation of uric acid concentrations in the blood of snakes is a crucial tool in the diagnosis of gout and renal disease; both prevalent diseases in captive reptiles. However, without an understanding of the physiological fluctuations in uric acid levels and the absence of distinction that makes pathological changes, biochemical parameters are devalued. This study focuses on investigating the relationship between feeding rate and plasma-uric acid concentrations of snakes. The aim of this investigation is to facilitate a better understanding of the feed-induced changes that occur, and to render the analysis of this biochemical parameter as a more potent diagnostic tool. A total of 10 snakes were used in the study and the basal concentration of uric acid was established prior to feeding via blood biochemical analysis. The snakes were then fed rats and successive postprandial blood samples were taken for the monitoring of uric acid levels. The results demonstrated that feeding led to substantial elevations in the uric acid values, whereby postprandial concentrations were significantly elevated for up to 5 days after feeding. The postprandial elevations in uric acid documented in these snakes were of similar levels reported in snakes afflicted with gout or renal disease. The results demonstrated the significant changes that occur to uric acid levels after feeding, and highlights the resemblance between postprandial increases in uric acid and concentrations reported in snakes suffering from renal disease or gout. To avoid a misdiagnosis and to distinguish transient postprandial hyperuricemia from pathological elevations, collecting sufficient anamnestic data on time since last feeding in performing repeated sampling after one week period of fasting is suggested.

Meat composition and quality of young growing Belgian Blue bulls offered a fattening diet with selenium enriched cereals

Mehdi, Y., Clinquart, A., Hornick, J.-L., Cabaraux, J.-F., Istasse, L. and Dufrasne, I. 2015. Meat composition and quality of young growing Belgian Blue bulls offered a fattening diet with selenium enriched cereals. Can. J. Anim. Sci. 95: 465–473. The objective of this study was to evaluate the effects of selenium (Se) enrichment of cereals on the performance of Belgian Blue bulls, meat quality and chemical composition. Twenty-three bulls were used in the present study. Twelve bulls were offered a control diet containing Se at a basal concentration of 58 µg kg−1 of dry matter (DM) and the other 11 bulls were given a diet containing 173 µg kg−1 DM of Se by means of Se-enriched spelt and barley. The Se enrichment of the diet did not affect the growth performance, the slaughter data or meat quality (P > 0.05). There were no effects of Se on tenderness, oxidative rancidity and water losses. However, there were some effects of Se enrichment on the meat chemical composition. The ether extract was decreased from 2.1 to 1.7% DM (P<0.05). There was also significant Se enrichment (P<0.001) in the longissimus thoracis muscle (177 vs. 477 ng g−1 DM) and organs: liver (474 vs. 1126 ng g−1 DM) and kidney (4956 vs. 5655 ng g−1 DM), Under such conditions, the human consumption of a piece of such meat or liver can provide a large part of the recommended daily Se intake, estimated between 30 and 57%.

Biological variation and prognosis usefulness of new biomarkers in liver transplantation

An observational retrospective study has been conducted, including 52 patients (37 male and 15 female), ranging from 22 to 65 years old, who underwent an orthotopic liver transplantation (OLT) at the Hospital Universitario Central de Asturias (HUCA) between 2007 and 2010.The main objective was to evaluate the post-OLT critical complication prognosis usefulness of the precursors of three new biomarkers: mid-regional proadrenomedullin (MR-proADM), carboxy-terminal-proendothelin-1 (CT-ProET-1) and mid-regional proatrial natriuretic peptide (MR-ProANP). As all of them are blood pressure mediators, stress-associated physiological phenomena are expected to affect their expression and secretion, mainly those related to blood circulation. Therefore, as a second goal, the biological variability of the biomarkers has been studied in a set of OLT patients without complications during the first postoperative week. The knowledge of the reference change value of the new biomarkers will be interesting for their correct interpretation in future investigations. The prognostic value of the new biomarkers was also compared to that of procalcitonin (PCT).It has been shown that the basal concentration of the biomarkers is higher in patients that undergo OLT than in the normal population, correlating with the severity of the pathology. The intra-individual biological variation of these biomarkers is similar to other biochemical parameters, the reference change value for OLT patients being 90% for CT-proET-1, 112% for MR-proADM and 127% for MR-proANP.Multivariate analysis showed that MR-proADM was the best biomarker for the prognosis of severe complications.