Un anévrysme sacciforme de l’aorte abdominale révélant une maladie de Behçet: quand faut-il opérer?

L'atteinte vasculaire est fréquente au cours de la maladie de Behçet. Elle est essentiellement représentée par les thromboses veineuses alors que l'atteinte artérielle est plus rare. Elle peut être isolée ou multifocale et peut toucher tous les territoires avec prédilection pour l’aorte abdominale, les artères pulmonaires et les artères des membres inférieurs. L'atteinte anévrysmale de l'aorte abdominale est trompeuse se manifestant par une symptomatologie atypique responsable d'un retard diagnostique favorisant la rupture. Dans notre cas, des douleurs abdominales paroxystiques ont incité le patient à consulter rapidement. L’enquête étiologique a conclue à un angio Behcet. Rarement, l’anévrysme de l’aorte abdominale est révélé par une complication telle que la rupture dans le rétro péritoine ou le tube digestif. Les indications chirurgicales des anévrysmes de l’aorte sont discutées ici. Un traitement immunosuppresseur au long cours s’impose en post opératoire pour limiter le risque de récidive

Seasonal variation of biochemical composition of Noah's ark shells (Arca noae L. 1758) in a Tunisian coastal lagoon in relation to its reproductive cycle and environmental conditions

The seasonal changes in biochemical composition of the edible bivalve Arca noae harvested from a Mediterranean coastal lagoon (Bizerte lagoon, Tunisia) were investigated from October 2013 to September 2014. Potential food sources and nutritional quality indices (NQI) were determined by analyzing the fatty acid profiles of their tissues during an annual reproductive cycle. Results showed that A. noae had moisture (73.8–82%) and protein (24.1–58.6% dry weight) as major components, followed by lipid (10.4–28.8% dry weight) and glycogen (4.05–14.6% dry weight). A. noae accumulated lipid and glycogen for gonadal development during both maturation periods (late autumn/late spring–summer) to be used during spawning periods (winter/late summer–early autumn). However, proteins were mainly used to support reproductive allocation and played an important role on the energetic maintenance. Lipid and glycogen were found to be significantly related to temperature, salinity and chlorophyll a (p < 0.05). An increase of condition index (CI) was observed during spring and early summer when both temperature and food supply increased. The total fatty acid (TFA) profile of Ark shells was dominated by polyunsaturated fatty acids (PUFA) (33.8–49.6%), followed by saturated (SFA) (29.1–43.1%) and monounsaturated fatty acids (MUFA) (20.77–28.3%). A. noae soft tissues were also rich in macro-minerals (Na, Ca and Mg). The analysis of fatty acid trophic markers revealed that the diet of A. noae during the year of study was based on mixture food mainly on phytoplankton followed by zooplankton and other sources (bacteria, seagrass and macroalgae). Furthermore, the nutritional quality indices have revealed that A. noae is an excellent source of nutrients and a healthy food for human consumption. These data are useful to the conservation of natural stocks of A. noae and the development of sustainable aquaculture production of this shellfish species in the Bizerte lagoon

Biomarker responses in the clam Ruditapes philippinarum to lead exposure

Trabajo presentado en el 41st CIESM Congress, celebrado en Kiel del 12 al 16 de septiembre de 2016.A lead exposure experiment (7 days) was carried out to determine the biomarker responses in the gills and digestive gland of the clam Ruditapes philippinarum. Non significant response was found in acetylcholinesterase (AChE), catalase (CAT), superoxidase dismutase (SOD) in both gills and digestive gland. On the contrary, phase II antioxidant enzyme (glutathione S -transferase, GST) and antioxidant enzyme, glutathione peroxidase (GPx) have shown significant variation after 7 days of exposure to 100μg/L Pb. GST was induced significantly (p<0.05), contrariwise, GPx was significantly (p<0.05) inhibited in the digestive gland. The present investigation showed that 10 μg/L Pb did not show any toxic effect on the clam R. philippinarum, while, 100μg/L could engender some oxidative stress variations.N

Biochemical response of the clam Ruditapes philippinarum to silver (AgD and AgNPs) exposure and application of an integrated biomarker response approach

Silver is a ubiquitous metal in the marine environment which can be accumulated by marine organisms. In order to assess the effect of dissolved silver (AgD) and AgNPs in R. philippinarum, the organisms were exposed to 20 μg L of AgD and AgNPs (15 nm) over 7 days. Bioaccumulation of the metal and oxidative and detoxification biomarkers were studied in control and exposed clams. Ag was accumulated in gills and digestive glands. Results for biochemical biomarkers (superoxide dismutase, catalase and glutathione reductase activity, lipid peroxidation and metallothionein provoked a general increase in the integrated biomarker response index (IBR) values) indicating the induction of oxidative stress in the clams exposed to both Ag treatments. Therefore, the presence of Ag forms at the tested concentration in the aquatic medium represent a risk for R. philippinarum.This study has been funded by the Junta de Andalucía (PE2011-RNM-7812 project) and Spanish National Research Plan MINECO (CTM2016-75908-R project)

Assessing lead toxicity in the clam Ruditapes philippinarum: Bioaccumulation and biochemical responses

Lead (Pb) is a non-essential metal. Its occurrence in the environment is related principally to anthropogenic contamination. Pb is toxic to aquatic organisms and can provoke damage to membranes and inhibit the activity of essential enzymes. The filter-feeding, Manila clam Ruditapes philippinarum is widely used as a biomonitor organism to assess metal toxicity. Among biomarkers related to the Pb toxicity, the enzymatic activity of δ-aminolevulinic acid dehydratase (δ-ALAD) has been adopted as a specific tool. Metallothionein (MT), lipid peroxidation (LPO) and antioxidant enzymes activities, such as catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) and superoxidase dismutase (SOD) have also been employed to assess the toxic effect of metals. Two target tissues, the gills and the digestive gland, were selected to examine biomarker responses. In order to assess the effects of Pb accumulation and the mechanisms involved in the recovery from it, clams were exposed at two Pb levels (10 and 100 µg/L) for 7 days and were later maintained in clean water for 7 days as a depuration period. Pb accumulation was dependent on the exposure concentration and higher Pb levels were observed in the gills compared to the digestive gland. Inhibition of δ-ALAD, GST and SOD and the induction of MT and LPO over the exposure period were observed in the gills and the digestive gland of R. philippinarum. The depuration period showed a continuous inhibition of the δ-ALAD activity and induction of MT and LPO in both tissues. These results demonstrate that lead induced an exposure effect and the 7 days of depuration were not sufficient to recover the basal health status of the clams.Peer reviewe

Short term exposure to permethrin alters lipid classes and fatty acid composition of the unfed clam Donax trunculus from Tunisian coast (Southern Mediterranean)

[EN] Permethrin (PER) is a pyrethroid insecticide widely used in agriculture. Dumped into the sea, this pollutant causes considerable harm to living organisms. The present study was undertaken to evaluate the toxic effects of PER, on the commercial clam Donax trunculus, largely distributed along the sandy beaches of the Gulf of Tunis. A toxicity assay (72 hours) using different PER concentrations (0, 50, 100 and 150 µg.L-1) was carried out to study the effects of the pesticide on lipid class and fatty acid composition of mantle and siphons of D. trunculus. Results showed a significant decrease in total lipid content with exposure to PER. An increase in the percentage of neutral lipids driven by a concomitant increase of triacylglycerols (TAG) was found after exposure. On the other hand, polar lipids decreased following mainly the fall of phosphatidylethanolamine (PE) and phosphatidylinositol (PI). The fatty acid content was also significantly altered in exposed D. trunculus. Saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA) and especially PUFA (n3) decreased significantly with PER exposure, while, monounsaturated fatty acids (MUFAs) showed significant decrease with 50 µg.L-1 and no significant difference between control (0 µg.L-1 PER) clams and those exposed to 100 and 150 µg.L-1.[FR] L’exposition de courte durée à la perméthrine altère les différentes classes de lipides ainsi que la composition en acides gras chez le mollusque Donax trunculus des côtes tunisiennes (Méditerranée méridionale). La perméthrine (PER), insecticide pyréthrinoïde, est un ingrédient actif synthétique qui a été largement utilisé dans l’agriculture. L’utilisation de ce polluant au voisinage des plans d’eau menace l’état de santé de ces écosystèmes. La présente étude avait comme objectif d’évaluer les effets toxiques de la PER sur le bivalve marin Donax trunculus, fréquemment rencontré sur les côtes sablonneuses du Golfe de Tunis. Un essai de toxicité à court terme (72 heures) a été réalisé. Trois doses de concentrations croissantes en PER (50, 100 et 150 µg.L-1) ont été utilisées pour voir leurs effets sur la composition en acides gras et en lipides de D. trunculus. Les résultats ont montré une importante diminution des teneurs en lipides totaux chez les spécimens exposés à la PER. En outre, une variation importante des pourcentages des différentes classes lipidiques a été également signalée après l’exposition. Cette variation consistait à une augmentation des pourcentages de lipides neutres, due principalement à celle des triacylglycérols (TAG), parallèlement à une diminution de ceux des lipides polaires représentés essentiellement par les phosphatidyléthanolamines (PE) et les phosphatidylinositoles (PI). Le profil des acides gras a été également modifié de façon significative chez D. trunculus après l’exposition à la PER. Les teneurs en acides gras saturés (AGS), en acides gras polyinsaturés (AGPI) et surtout en AGPI (n-3) ont diminué de manière significative avec l’exposition, tandis que, celles des acides gras mono-insaturés (AGMI) ont chuté seulement après l’exposition à 50 µg.L-1This study was supported by the Tunis University of Sciences, the Biology Department, the research Unit of Physiology and aquatic environment and the institute of aquaculture of Torre de la Sal, SpainPeer reviewe

Changes in lipid classes, fatty acid composition and lipid peroxidation in the gills of the clam donax trunculus after permethrin exposure

Trabajo presentado en el 41 Congrès de la Commission Internationale pour l'Exploration Scientifique de la mer Méditerranée (CIESM), celebrado en Kiel (Alemania) del 12 al16 septiembre de 2016A short term exposure experiment (72 h) to permethrin (PER) of the clam Donax trunculus from the Tunisian coast was carried out. Changes in the lipid classes, fatty acid (FA) composition and lipid peroxidation were determined in the gills of adults and juveniles. A significant decrease of total lipid content was followed by a decrease in polar lipids (PL) and polyunsaturated fatty acids (PUFAs) especially n-3 and n-6. As, for the oxidative stress response, a significant elevation in lipid peroxidation (LPO) was found after the exposure of both adults and juveniles.Peer reviewe

Seasonal variation of biochemical composition of Noah's ark shells (

The seasonal changes in biochemical composition of the edible bivalve Arca noae harvested from a Mediterranean coastal lagoon (Bizerte lagoon, Tunisia) were investigated from October 2013 to September 2014. Potential food sources and nutritional quality indices (NQI) were determined by analyzing the fatty acid profiles of their tissues during an annual reproductive cycle. Results showed that A. noae had moisture (73.8–82%) and protein (24.1–58.6% dry weight) as major components, followed by lipid (10.4–28.8% dry weight) and glycogen (4.05–14.6% dry weight). A. noae accumulated lipid and glycogen for gonadal development during both maturation periods (late autumn/late spring–summer) to be used during spawning periods (winter/late summer–early autumn). However, proteins were mainly used to support reproductive allocation and played an important role on the energetic maintenance. Lipid and glycogen were found to be significantly related to temperature, salinity and chlorophyll a (p < 0.05). An increase of condition index (CI) was observed during spring and early summer when both temperature and food supply increased. The total fatty acid (TFA) profile of Ark shells was dominated by polyunsaturated fatty acids (PUFA) (33.8–49.6%), followed by saturated (SFA) (29.1–43.1%) and monounsaturated fatty acids (MUFA) (20.77–28.3%). A. noae soft tissues were also rich in macro-minerals (Na, Ca and Mg). The analysis of fatty acid trophic markers revealed that the diet of A. noae during the year of study was based on mixture food mainly on phytoplankton followed by zooplankton and other sources (bacteria, seagrass and macroalgae). Furthermore, the nutritional quality indices have revealed that A. noae is an excellent source of nutrients and a healthy food for human consumption. These data are useful to the conservation of natural stocks of A. noae and the development of sustainable aquaculture production of this shellfish species in the Bizerte lagoon