Effect of fructose overfeeding and fish oil administration on hepatic de novo lipogenesis and insulin sensitivity in healthy men.

High-fructose diet stimulates hepatic de novo lipogenesis (DNL) and causes hypertriglyceridemia and insulin resistance in rodents. Fructose-induced insulin resistance may be secondary to alterations of lipid metabolism. In contrast, fish oil supplementation decreases triglycerides and may improve insulin resistance. Therefore, we studied the effect of high-fructose diet and fish oil on DNL and VLDL triglycerides and their impact on insulin resistance. Seven normal men were studied on four occasions: after fish oil (7.2 g/day) for 28 days; a 6-day high-fructose diet (corresponding to an extra 25% of total calories); fish oil plus high-fructose diet; and control conditions. Following each condition, fasting fractional DNL and endogenous glucose production (EGP) were evaluated using [1-13C]sodium acetate and 6,6-2H2 glucose and a two-step hyperinsulinemic-euglycemic clamp was performed to assess insulin sensitivity. High-fructose diet significantly increased fasting glycemia (7 +/- 2%), triglycerides (79 +/- 22%), fractional DNL (sixfold), and EGP (14 +/- 3%, all P < 0.05). It also impaired insulin-induced suppression of adipose tissue lipolysis and EGP (P < 0.05) but had no effect on whole- body insulin-mediated glucose disposal. Fish oil significantly decreased triglycerides (37%, P < 0.05) after high-fructose diet compared with high-fructose diet without fish oil and tended to reduce DNL but had no other significant effect. In conclusion, high-fructose diet induced dyslipidemia and hepatic and adipose tissue insulin resistance. Fish oil reversed dyslipidemia but not insulin resistance.

The weaker points of fish acute toxicity tests and how tests on embryos can solve some issues.

Fish acute toxicity tests play an important role in environmental risk assessment and hazard classification because they allow for first estimates of the relative toxicity of various chemicals in various species. However, such tests need to be carefully interpreted. Here we shortly summarize the main issues which are linked to the genetics and the condition of the test animals, the standardized test situations, the uncertainty about whether a given test species can be seen as representative to a given fish fauna, the often missing knowledge about possible interaction effects, especially with micropathogens, and statistical problems like small sample sizes and, in some cases, pseudoreplication. We suggest that multi-factorial embryo tests on ecologically relevant species solve many of these issues, and we shortly explain how such tests could be done to avoid the weaker points of fish acute toxicity tests.

Effects of fish oil on the neuro-endocrine responses to an endotoxin challenge in healthy volunteers

Résumé Introduction et hypothèse : Certains acides gras polyinsaturés de type n-3 PUFA, qui sont contenus dans l'huile de poisson, exercent des effets non-énergétiques (fluidité des membranes cellulaires, métabolisme énergétique et prostanoïdes, régulation génique de la réponse inflammatoire). Les mécanismes de la modulation de cette dernière sont encore mal connus. L'administration d'endotoxine (LPS) induit chez les volontaires sains une affection inflammatoire aiguë, comparable à un état grippal, associé à des modifications métaboliques et inflammatoires transitoires, similaires au sepsis. Ce modèle est utilisé de longue date pour l'investigation clinique expérimentale. Cette étude examine les effets d'une supplémentation orale d'huile de poisson sur la réponse inflammatoire (systémique et endocrinienne) de sujets sains soumis à une injection d'endotoxine. L'hypothèse était que la supplémentation d'huile de poisson réduirait les réponses physiologiques à l'endotoxine. Méthodes : Quinze volontaires masculins (âge 26.0±3.1 ans) ont participé à une étude randomisée, contrôlée. Les sujets sont désignés au hasard à recevoir ou non une supplémentation orale : 7.2 g d'huile de poisson par jour correspondant à un apport de 1.1 g/jour d'acides gras 20:5 (n-3, acide écosapentaénoïque) et 0.7 g/jour de 22:6 (n-3, acide docosahexaénoïque). Chaque sujet est investigué deux fois dans des conditions identiques : une fois il reçoit une injection de 2 ng par kg poids corporel de LPS intraveineuse, l'autre fois une injection de placebo. Les variables suivantes sont relevées avant l'intervention et durant les 360 min qui suivent l'injection :signes vitaux, dépense énergétique (EE) et utilisation nette des substrats (calorimétrie indirecte, cinétique du glucose (isotopes stables), taux plasmatique des triglycérides et FFA, du glucose, ainsi que des cytokines et hormones de stress (ACTH, cortisol, Adré, Nor-Adré). Analyses et statistiques :moyennes, déviations standards, analyse de variance (one way, test de Scheffé), différences significatives entre les groupes pour une valeur de p < 0.05. Résultats :L'injection de LPS provoque une augmentation de la température, de la fréquence cardiaque, de la dépense d'énergie et de l'oxydation nette des lipides. On observe une élévation des taux plasmatiques de TNF-a et IL-6, de la glycémie, ainsi qu'une élévation transitoire des concentrations plasmatiques des hormones de stress ACTH, cortisol, adrénaline et noradrénaline. L'huile de poisson atténue significativement la fièvre, la réponse neuro-endocrinienne (ACTH et cortisol) et sympathique (baisse de la noradrénaline plasmatique). Par contre, les taux des cytokines ne sont pas influencés par la supplémentation d'huile de poisson. Conclusion : La supplémentation d'huile de poisson atténue la réponse physiologique à l'endotoxine chez le sujet sain, en particulier la fièvre et la réponse endocrinienne, sans influencer la production des cytokines. Ces résultats soutiennent l'hypothèse que les effets bénéfiques de l'huile de poisson sont principalement caractérisés au niveau du système nerveux central, par des mécanismes non-inflammatoires qui restent encore à élucider.

Accurate memory for object location by individuals with intellectual disability: Absolute spatial tagging instead of configural processing?

Using head-mounted eye tracker material, we assessed spatial recognition abilities (e.g., reaction to object permutation, removal or replacement with a new object) in participants with intellectual disabilities. The "Intellectual Disabilities (ID)" group (n=40) obtained a score totalling a 93.7% success rate, whereas the "Normal Control" group (n=40) scored 55.6% and took longer to fix their attention on the displaced object. The participants with an intellectual disability thus had a more accurate perception of spatial changes than controls. Interestingly, the ID participants were more reactive to object displacement than to removal of the object. In the specific test of novelty detection, however, the scores were similar, the two groups approaching 100% detection. Analysis of the strategies expressed by the ID group revealed that they engaged in more systematic object checking and were more sensitive than the control group to changes in the structure of the environment. Indeed, during the familiarisation phase, the "ID" group explored the collection of objects more slowly, and fixed their gaze for a longer time upon a significantly lower number of fixation points during visual sweeping.

Effects of recreational fishing on three fish species from the Posidonia oceanica meadows off Minorca (Balearic archipelago, western Mediterranean)

Experimental fishing and visual censuses were conducted at nine Posidonia oceanica sites off Minorca exposed to different levels of fishing intensity to assess the effects of recreational fishing on the species that dominate the catch. Total catch per unit effort (CPUE) was highly seasonal and a statistically significant interaction term existed between the season and the level of fishing intensity. CPUE decreased everywhere at the end of the fishing season (autumn), but such a reduction was more intense at those sites exposed to the highest level of fishing. Visual censuses confirmed that there was a lower abundance of vulnerable fish in autumn. Differences vanished in spring probably because fish reshuffled between the considered sites throughout the winter, when the level of fishing intensity was extremely low. Although the average total lengths of Serranus scriba and Diplodus annularis were unaffected by the level of fishing intensity, the average total length of Coris julis was smaller at the most heavily fished sites. In conclusion, recreational fishing has a relevant impact on most of the exploited species and some of the seasonality reported for the Posidonia oceanica fish assemblages might be caused by the seasonality of the fishery.

Semantic domains and supersens tagging for domain-specific ontology learning

In this paper we propose a novel unsupervised approach to learning domain-specific ontologies from large open-domain text collections. The method is based on the joint exploitation of Semantic Domains and Super Sense Tagging for Information Retrieval tasks. Our approach is able to retrieve domain specific terms and concepts while associating them with a set of high level ontological types, named supersenses, providing flat ontologies characterized by very high accuracy and pertinence to the domain.

Quantification of the local heartwall motion by magnetic resonance myocardial tagging.

Sophisticated magnetic resonance tagging techniques provide powerful tools for the non-invasive assessment of the local heartwall motion towards a deeper fundamental understanding of local heart function. For the extraction of motion data from the time series of magnetic resonance tagged images and for the visualization of the local heartwall motion a new image analysis procedure has been developed. New parameters have been derived which allows quantification of the motion patterns and are highly sensitive to any changes in these patterns. The new procedure has been applied for heart motion analysis in healthy volunteers and in patient collectives with different heart diseases. The achieved results are summarized and discussed.

Vitamin E content in fish oil emulsion does not prevent lipoperoxidative effects on human colorectal tumors.

OBJECTIVE: The anticancer action exerted by polyunsaturated fatty acid peroxidation may not be reproduced by commercially available lipid emulsions rich in vitamin E. Therefore, we evaluated the effects of fish oil (FO) emulsion containing α-tocopherol 0.19 g/L on human colorectal adenocarcinoma cells and tumors. METHODS: HT-29 cell growth, survival, apoptosis, and lipid peroxidation were analyzed after a 24-h incubation with FO 18 to 80 mg/L. Soybean oil (SO) emulsion was used as an isocaloric and isolipidic control. In vivo, nude mice bearing HT-29 tumors were sacrificed 7 d after an 11-d treatment with intravenous injections of FO or SO 0.2 g ∙ kg(-1) ∙ d(-1) FO or SO to evaluate tumor growth, necrosis, and lipid peroxidation. RESULTS: The FO inhibited cell viability and clonogenicity in a dose-dependent manner, whereas SO showed no significant effect compared with untreated controls. Lipid peroxidation and cell apoptosis after treatment with FO 45 mg/L were increased 2.0-fold (P < 0.01) and 1.6-fold (P = 0.04), respectively. In vivo, FO treatment did not significantly affect tumor growth. However, immunohistochemical analyses of tumor tissue sections showed a decrease of 0.6-fold (P < 0.01) in the cell proliferation marker Ki-67 and an increase of 2.3-fold (P = 0.03) in the necrotic area, whereas malondialdehyde and total peroxides were increased by 1.9-fold (P = 0.09) and 7.0-fold (P < 0.01), respectively, in tumors of FO-treated compared with untreated mice. CONCLUSION: These results suggest that FO but not SO has an antitumor effect that can be correlated with lipid peroxidation, despite its vitamin E content.

Geometric morphometric analyses provide evidence for the adaptive character of the Tanganyikan cichlid fish radiations.

The cichlids of East Africa are renowned as one of the most spectacular examples of adaptive radiation. They provide a unique opportunity to investigate the relationships between ecology, morphological diversity, and phylogeny in producing such remarkable diversity. Nevertheless, the parameters of the adaptive radiations of these fish have not been satisfactorily quantified yet. Lake Tanganyika possesses all of the major lineages of East African cichlid fish, so by using geometric morphometrics and comparative analyses of ecology and morphology, in an explicitly phylogenetic context, we quantify the role of ecology in driving adaptive speciation. We used geometric morphometric methods to describe the body shape of over 1000 specimens of East African cichlid fish, with a focus on the Lake Tanganyika species assemblage, which is composed of more than 200 endemic species. The main differences in shape concern the length of the whole body and the relative sizes of the head and caudal peduncle. We investigated the influence of phylogeny on similarity of shape using both distance-based and variance partitioning methods, finding that phylogenetic inertia exerts little influence on overall body shape. Therefore, we quantified the relative effect of major ecological traits on shape using phylogenetic generalized least squares and disparity analyses. These analyses conclude that body shape is most strongly predicted by feeding preferences (i.e., trophic niches) and the water depths at which species occur. Furthermore, the morphological disparity within tribes indicates that even though the morphological diversification associated with explosive speciation has happened in only a few tribes of the Tanganyikan assemblage, the potential to evolve diverse morphologies exists in all tribes. Quantitative data support the existence of extensive parallelism in several independent adaptive radiations in Lake Tanganyika. Notably, Tanganyikan mouthbrooders belonging to the C-lineage and the substrate spawning Lamprologini have evolved a multitude of different shapes from elongated and Lamprologus-like hypothetical ancestors. Together, these data demonstrate strong support for the adaptive character of East African cichlid radiations.

Combining protein identification and quantification: C-terminal isotope-coded tagging using sulfanilic acid.

Two methods of differential isotopic coding of carboxylic groups have been developed to date. The first approach uses d0- or d3-methanol to convert carboxyl groups into the corresponding methyl esters. The second relies on the incorporation of two 18O atoms into the C-terminal carboxylic group during tryptic digestion of proteins in H(2)18O. However, both methods have limitations such as chromatographic separation of 1H and 2H derivatives or overlap of isotopic distributions of light and heavy forms due to small mass shifts. Here we present a new tagging approach based on the specific incorporation of sulfanilic acid into carboxylic groups. The reagent was synthesized in a heavy form (13C phenyl ring), showing no chromatographic shift and an optimal isotopic separation with a 6 Da mass shift. Moreover, sulfanilic acid allows for simplified fragmentation in matrix-assisted laser desorption/ionization (MALDI) due the charge fixation of the sulfonate group at the C-terminus of the peptide. The derivatization is simple, specific and minimizes the number of sample treatment steps that can strongly alter the sample composition. The quantification is reproducible within an order of magnitude and can be analyzed either by electrospray ionization (ESI) or MALDI. Finally, the method is able to specifically identify the C-terminal peptide of a protein by using GluC as the proteolytic enzyme.

Microfabricated dual sprayer for on-line mass tagging of phosphopeptides.

Phosphopeptides tagging reactions by dinuclear zinc(II) complexes (1,3-bis[bis(2-pyridylmethyl)amino]-propan-2-olato dizinc(II)3+, called tag) were performed with a dual-channel microsprayer in electrospray ionization mass spectrometry. The reaction is first studied ex situ and analyzed with a commercial electrospray source. In situ reactions (i.e., inside the Taylor cone) were achieved with a dual-channel microsprayer both with the tag synthesized chemically before the experiments and with the tag electrogenerated by in situ oxidation of a zinc electrode, also used to apply the electrospray current. The device consists of a polyimide microchip with two microchannels (20 microm x 50 microm x 1 cm) etched on each side of the structure and connecting only at the tip of the microchip. We demonstrate here that mixing two solutions with different physicochemical properties inside the Taylor cone can be used to selectively tag target molecules.

Spermiogenesis and spermatozoon ultrastructure of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Gadiformes: Merlucciidae)

Spermiogenesis and the ultrastructure of the spermatozoon of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Linnaeus, 1758), have been studied by means of transmission electron microscopy. Spermiogenesis involves firstly the formation of a differentiation zone. It is characterized by the presence of two centrioles associated with striated rootlets, an intercentriolar body and an electron-dense material in the apical region of this zone. Later, two flagella develop from the centrioles, growing orthogonally in relation to the median cytoplasmic process. Flagella then undergo a rotation of 90° until they become parallel to the median cytoplasmic process, followed by the proximodistal fusion of the flagella with the median cytoplasmic process. The nucleus elongates and afterwards it migrates along the spermatid body. Spermiogenesis finishes with the appearance of the apical cone surrounded by the single helical crested body at the base of the spermatid. Finally, the narrowing of the ring of arched membranes detaches the fully formed spermatozoon. The mature spermatozoon of C. crassiceps is filiform and contains two axonemes of the 9 + '1' trepaxonematan pattern, a parallel nucleus, parallel cortical microtubules, and electron-dense granules of glycogen. The anterior extremity of the gamete exhibits a short electron-dense apical cone and one crested body, which turns once around the sperm cell. The first axoneme is surrounded by a ring of thick cortical microtubules that persist until the appearance of the second axoneme. Later, these thick cortical microtubules disappear and thus, the mature spermatozoon exhibits two bundles of thin cortical microtubules. The posterior extremity of the male gamete presents only the nucleus. Results are discussed and compared particularly with the available ultrastructural data on the former 'pseudophyllideans'. Two differences can be established between spermatozoa of Bothriocephalidea and Diphyllobothriidea, the type of spermatozoon (II vs I) and the presence/absence of the ring of cortical microtubules.