348 research outputs found

    Oxidative stress and hepatotoxicity in rats induced by poisonous pufferfish (Lagocephalus lagocephalus) meat

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    This study was undertaken to evaluate the effect of pufferfish (Lagocephalus lagocephalus) meat poisoning on hepatic functions of Wistar rats. For this purpose, groups of rats (Lcr, Lcu+b and Lcu-b) received diet supplemented with 10% of raw or cooked meat, respectively, with or without cooking water of L. lagocephalus while groups Mcr and Mcu+b received diet supplemented with 10% of raw or cooked meat of Liza aurata, which were used as a negative control. In Lcu+b group, ALT, AST and ALP rates (hepatic enzyme markers) decreased after two months of treatment, indicating liver damage. We also observed an increase of 54 and 65% of thiobarbituric acid reactive substances (TBARS) in their livers respectively 48 hours and two months after treatment compared to controls. The catalase (CAT) activity in group Lcu+b decreased (p < 0.05) after two periods of treatment, whereas metallothionein (MT) level significantly increased and decreased, respectively after 48 hours and two months. In fact, in the histological analysis of the livers from Lcu+b treated group, we observed an increase in vacuolisation, necrosis, hepatocytes ballooning and sinusoids dilation. These results indicate that L. lagocephalus meat cooked with water produces hepatotoxicity and oxidative damage

    Extracted tetrodotoxin from puffer fish Lagocephalus lagocephalus induced hepatotoxicity and nephrotoxicity to Wistar rats

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    This study aimed to investigate the toxicity of raw and boiled tissue extracts of Lagocephalus lagocephalus flesh or liver. Five groups of six male Wistar rats each were used. Four groups received a daily intraperitoneal injection of raw or boiled tissue extracts of L. lagocephalus flesh and liver at a dose of 1 ml/100 g (v/w). The fifth group served as a sham and received a daily intraperitoneal injection of saline solution (1 ml/100 g of 0.9% NaCl, v/w). During the experiment, there was a slight decrease in body weight in all treated groups. Our results revealed that the activities of various enzymes like transaminase, alkaline phosphatase (ALP), gamma glutamyl transpeptidase (γ-GT) and lactate dehydrogenase (LDH) decreased in serum and increased in liver and kidney tissues, producing hepatotoxicity and nephrotoxicity in the treated rats. These observations on the toxicity of this Tunisian puffer fish revealing toxicity especially in the flesh, the edible part of fish, clearly indicate the danger of using this fish as food.Key words: Hepatotoxicity, Lagocephalus lagocephalus, nephrotoxicity

    Effect of Phase Contrast and Geometrical Parameters on Bending Behavior of Sandwich Beams with FG Isotropic Face Sheets

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    Our work is to study the bending behavior of sandwich beams with functional gradient by constituting an isotropic material whose material properties vary smoothly in the z direction only (FGM), where the central layer presents purely a homogeneous and isotropic ceramic. The mechanical properties of FG sandwich beams are assumed to be progressive in thickness according to a power law (P-FGM). Generally, the principle of virtual works is used to obtain the equilibrium equations, and their solutions are obtained based on Navier's solution technique. The present model is based on a shear deformation theory of 2D and 3D beams which contains four unknowns to extract the equilibrium equations of FG sandwich beams. In addition, analytical solutions for bending are used and numerical models are presented to verify the accuracy of the present theory. All the results obtained show that the stiffness of the FG beam decreases as a function of the increase in the volume fraction index k, leading to an increase in the deflections. However, FG beams become flexible by increasing the proportion of the metal to the ceramic part. Furthermore, the influences of material volume fraction index, layer thickness ratio, side-to-height ratio, and the effect of the phase contrast, on the deflections, normal and shear stress of simply supported sandwich FG beams are taken into investigation and discussed in detail. Finally, all our results obtained are in agreement with other previous theoretical works

    Pre-transplant CD45RC expression on blood T cells differentiates patients with cancer and rejection after kidney transplantation

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    Background Biological biomarkers to stratify cancer risk before kidney transplantation are lacking. Several data support that tumor development and growth is associated with a tolerant immune profile. T cells expressing low levels of CD45RC preferentially secrete regulatory cytokines and contain regulatory T cell subset. In contrast, T cells expressing high levels of CD45RC have been shown to secrete proinflammatory cytokines, to drive alloreactivity and to predict acute rejection (AR) in kidney transplant patients. In the present work, we evaluated whether pre-transplant CD45RClow T cell subset was predictive of post-transplant cancer occurrence. Methods We performed an observational cohort study of 89 consecutive first time kidney transplant patients whose CD45RC T cell expression was determined by flow cytometry before transplantation. Post-transplant events including cancer, AR, and death were assessed retrospectively. Results After a mean follow-up of 11.1±4.1 years, cancer occurred in 25 patients (28.1%) and was associated with a decreased pre-transplant proportion of CD4+CD45RChigh T cells, with a frequency below 51.9% conferring a 3.7-fold increased risk of post-transplant malignancy (HR 3.71 [1.24–11.1], p = 0.019). The sensibility, specificity, negative predictive and positive predictive values of CD4+CD45RChigh&lt;51.9% were 84.0, 54.7, 89.8 and 42.0% respectively. Confirming our previous results, frequency of CD8+CD45RChigh T cells above 52.1% was associated with AR, conferring a 20-fold increased risk (HR 21.7 [2.67–176.2], p = 0.0004). The sensibility, specificity, negative predictive and positive predictive values of CD8+CD45RChigh&gt;52.1% were 94.5, 68.0, 34.7 and 98.6% respectively. Frequency of CD4+CD45RChigh T cells was positively correlated with those of CD8+CD45RChigh (p&lt;0.0001), suggesting that recipients with high AR risk display a low cancer risk. Conclusion High frequency of CD45RChigh T cells was associated with AR, while low frequency was associated with cancer. Thus, CD45RC expression on T cells appears as a double-edged sword biomarker of promising interest to assess both cancer and AR risk before kidney transplantation

    Health promoting potential of herbal teas and tinctures from Artemisia campestris subsp maritima: from traditional remedies to prospective products

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    This work explored the biotechnological potential of the medicinal halophyte Artemisia campestris subsp. maritima (dune wormwood) as a source of health promoting commodities. For that purpose, infusions, decoctions and tinctures were prepared from roots and aerial-organs and evaluated for in vitro antioxidant, anti-diabetic and tyrosinase-inhibitory potential, and also for polyphenolic and mineral contents and toxicity. The dune wormwood extracts had high polyphenolic content and several phenolics were identified by ultra-high performance liquid chromatography-photodiode array-mass-spectrometry (UHPLC-PDA-MS). The main compounds were quinic, chlorogenic and caffeic acids, coumarin sulfates and dicaffeoylquinic acids; several of the identified phytoconstituents are here firstly reported in this A. campestris subspecies. Results obtained with this plant's extracts point to nutritional applications as mineral supplementary source, safe for human consumption, as suggested by the moderate to low toxicity of the extracts towards mammalian cell lines. The dune wormwood extracts had in general high antioxidant activity and also the capacity to inhibit a-glucosidase and tyrosinase. In summary, dune wormwood extracts are a significant source of polyphenolic and mineral constituents, antioxidants and a-glucosidase and tyrosinase inhibitors, and thus, relevant for different commercial segments like the pharmaceutical, cosmetic and/or food industries.FCT - Foundation for Science and Technology [CCMAR/Multi/04326/2013]; Portuguese National Budget; FCT [IF/00049/2012, SFRH/BD/94407/2013]; Research Foundation - Flanders (FWO) [12M8315N]info:eu-repo/semantics/publishedVersio

    High-Capacity Conductive Nanocellulose Paper Sheets for Electrochemically Controlled Extraction of DNA Oligomers

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    Highly porous polypyrrole (PPy)-nanocellulose paper sheets have been evaluated as inexpensive and disposable electrochemically controlled three-dimensional solid phase extraction materials. The composites, which had a total anion exchange capacity of about 1.1 mol kg−1, were used for extraction and subsequent release of negatively charged fluorophore tagged DNA oligomers via galvanostatic oxidation and reduction of a 30–50 nm conformal PPy layer on the cellulose substrate. The ion exchange capacity, which was, at least, two orders of magnitude higher than those previously reached in electrochemically controlled extraction, originated from the high surface area (i.e. 80 m2 g−1) of the porous composites and the thin PPy layer which ensured excellent access to the ion exchange material. This enabled the extractions to be carried out faster and with better control of the PPy charge than with previously employed approaches. Experiments in equimolar mixtures of (dT)6, (dT)20, and (dT)40 DNA oligomers showed that all oligomers could be extracted, and that the smallest oligomer was preferentially released with an efficiency of up to 40% during the reduction of the PPy layer. These results indicate that the present material is very promising for the development of inexpensive and efficient electrochemically controlled ion-exchange membranes for batch-wise extraction of biomolecules

    Algorithme rapide de codage conjoint source-canal pour un canal de transmission non-stationnaire

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    Dans cet article, nous proposons l'algorithme RGSKAε qui permet de construire un dictionnaire qui est optimal dans le cas où il n'y a pas de bruit de transmission et qui est aussi robuste vis-à-vis des erreurs de transmission de tous niveaux. Cet algorithme stochastique ne nécessite aucune connaissance a priori du signal à quantifier et du canal de transmission. Il est indépendant du dictionnaire initial et il est capable de sortir de minima locaux. L'exigence de temps de construction est comparable avec celle de l'algorithme de la k-moyenne (KMA). La mise en oeuvre de l'algorithme RGSKAε est aussi simple que celle de l'algorithme KMA car tous ses paramètres sont fixés, ils ne dépendent pas du type ou de la taille des vecteurs à quantifier. L'algorithme RGSKAε possède des propriétés de convergence très avantageuses: il permet de construire un dictionnaire bien équilibré même si le nombre des vecteurs d'apprentissage est inférieur à la taille du dictionnaire
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