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This review summarizes the current knowledge on the contribution of metals to the development of oxidative stress in fish. Metals are important inducers of oxidative stress in aquatic organisms, promoting formation of reactive oxygen species through two mechanisms. Redox active metals generate reactive oxygen species through redox cycling, while metals without redox potential impair antioxidant defences, especially that of thiol-containing antioxidants and enzymes. Elevated levels of reactive oxygen species lead to oxidative damage including lipid peroxidation, protein and DNA oxidation, and enzyme inactivation. Antioxidant defences include the enzyme system and low molecular weight antioxidants. Metal-binding proteins, such as ferritin, ceruloplasmin and metallothioneins, have special functions in the detoxification of toxic metals and also play a role in the metabolism and homeostasis of essential metals. Recent studies of metallothioneins as biomarkers indicate that quantitative analysis of mRNA expression of metallothionein genes can be appropriate in cases with elevated levels of metals and no evidence of oxidative damage in fish tissue. Components of the antioxidant defence are used as biochemical markers of oxidative stress. These markers may be manifested differently in the field than in results found in laboratory studies. A complex approach should be taken in field studies of metal contamination of the aquatic environment.

Advances in molecular biology and toxicology are paving the way for major improvements in the evaluation of the hazards posed by the large number of chemicals found at low levels in the environment. The National Research Council was asked by the U.S. Environmental Protection Agency to review the state of the science and create a far-reaching vision for the future of toxicity testing. The book finds that developing, improving, and validating new laboratory tools based on recent scientific advances could significantly improve our ability to understand the hazards and risks posed by chemicals. This new knowledge would lead to much more informed environmental regulations and dramatically reduce the need for animal testing because the new tests would be based on human cells and cell components. Substantial scientific efforts and resources will be required to leverage these new technologies to realize the vision, but the result will be a more efficient, informative and less costly system for assessing the hazards posed by industrial chemicals and pesticides.

This article presents a review describing the main mycotoxins encountered in pig feed which have a negative impact on sow fertility and reproduction. Consumption of feed that is contaminated with these mycotoxins may cause a variety of symptoms, depending on the type of mycotoxin, quantity and duration of exposure, as well as the health status and condition of the animal at the time of exposure. Two types of fungi are recognized, field fungi and storage fungi. Field fungi such as Fusarium spp., Aspergillus spp. and Claviceps spp. may produce toxins that lead to disturbed reproductive performance. Storage fungi occur if the humidity during storage is too high. In daily practice, the symptoms related to mycotoxicosis can occur at toxin concentrations below the detection limit. Mycotoxins may still be present in feedstuffs despite negative analytical findings and because of the presence of hot spots in feedstuffs. Clinical symptoms can be very pronounced or vague. The main toxins causing reproductive failure discussed in this article are aflatoxins, ergot alkaloids, trichothecenes and zearalenone.

The effect of bifenthrin on rainbow trout was assessed based on biochemical, haematological and histopathological examination of fish exposed to Talstar 10 EC pesticide preparation (100 g/L bifenthrin) at a concentration of 14.7 microg/L. There was a significant decrease in plasma ammonia, significant increase in glucose, creatine kinase, alkaline phosphatase and lactate dehydrogenase. Fish showed a significant decrease in mean erythrocyte volume, erythrocyte haemoglobin, and band neutrophil granulocytes. Degeneration of hepatocytes was observed histologically. The bifenthrin-based Talstar 10 EC pesticide preparation was therefore classified as a substance strongly toxic to fish.

Cadmium, lead, mercury, and aluminum are toxic metals that may interact metabolically with nutritionally essential metals. Iron deficiency increases absorption of cadmium, lead, and aluminum. Lead interacts with calcium in the nervous system to impair cognitive development. Cadmium and aluminum interact with calcium in the skeletal system to produce osteodystrophies. Lead replaces zinc on heme enzymes and cadmium replaces zinc on metallothionein. Selenium protects from mercury and methylmercury toxicity. Aluminum interacts with calcium in bone and kidneys, resulting in aluminum osteodystrophy. Calcium deficiency along with low dietary magnesium may contribute to aluminum-induced degenerative nervous disease

Acute toxicity tests were carried out in order to assess the effect of cypermethrin on rainbow trout. Results of haematological, biochemical and histopathological tissue examinations of control and experimental groups exposed to Alimetrine 10 EM pesticide preparation (active substance 100 g/L of cypermethrin) were compared. An acute semistatical toxicity test lasting 96 h was performed on rainbow trout juveniles. The 96hLC50 value of Alimethrine 10 EM was 31.4 microg/L. In comparison with control animals, the experimental group showed significantly higher values of plasma ammonia, aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and lactate, and significantly lower values of alkaline phosphatase. A significant decrease in counts of developmental forms of myeloid sequence and segmented neutrophile granulocytes was found in the experimental group. Teleangioectasiae of secondary gill lamellae and degeneration of hepatocytes were observed. No histopathological changes were demonstrated in skin, spleen, cranial and caudal kidney tissues. The cypermethrine-based Alimethrinee 10 EM pesticide preparation was classified as a substance strongly toxic for fish.

Le manioc fait partie des principales plantes à racines amylacées cultivées dans le monde. En 2008, la production totale de manioc en Afrique de l’Ouest représentait 29 % de la production mondiale. Cependant, dans certains pays de cette région comme le Sénégal, le manioc n’a pas encore connu un réel développement dans l’alimentation de base de sa population. En effet, les potentialités d’utilisation alimentaire du manioc ne sont pas assez connues. Par ailleurs, la composition chimique et la toxicité des variétés locales consommées restent à déterminer. En 2004, le Gouvernement avait initié une vaste campagne d’intensification de la production nationale en manioc pour remédier au problème de sécurité alimentaire, car cette denrée constitue une importante source de calories et une intéressante option face aux céréales importées comme le riz et le blé. De nombreux produits dérivés du manioc sont connus dans la sous-région et dans les marchés internationaux mais au Sénégal, ces produits sont limités et, par conséquent, le niveau de consommation est très faible. Parfois, ils sont retrouvés dans certains restaurants où Sénégalais et autres Africains les consomment. L’objectif de cette étude est de montrer la valeur nutritionnelle et les potentialités de valorisation des racines de manioc pour l’alimentation de base au Sénégal. Cassava is one of the main plants and starchy roots grown in the world. In 2008, the total yield of cassava in West Africa represented 29% of the world production. However, in many West African countries such as Senegal, cassava is not used as a staple food. In fact, the processing techniques used for cassava are poorly known. In addition, the chemical composition of local cassava varieties has not yet been determined, nor has their toxicity been assessed. In 2004, showing an aggressive agricultural policy and revived interest, the Senegalese government launched a major program for intensifying the production of cassava for food security purposes. Cassava is an important source of calories and can be an interesting option for imported rice and wheat. Although many food products made from cassava are well known in the region, their use in the Senegalese diet is rare. Nevertheless, these cassava products are found as delicacies in some restaurants, and are consumed by the Senegalese and many other Africans. The objective of the present study is to demonstrate the nutritional value and the dietary possibilities of using cassava as a staple food in Senegal.

The article presents current view on the effects of ozone on the ultrastructure of plant cells, changes in winter hardiness and on some of the resistance responses of cells to the toxicity of this gas and its derivates

Modification of low density lipoprotein (LDL) by free radical oxidation renders this molecular complex cytotoxic. Oxidized lipoproteins exist in vivo in atherosclerotic lesions and in the plasma of diabetic animals, suggesting that lipoprotein induced tissue damage may occur in certain diseases. We undertook purification and identification of the major cytotoxin in oxidized LDL. The lipid extract from oxidized LDL was subjected to multiple HPLC separations, and the fractions were assayed for cytotoxicity. Mass spectrometry and nuclear magnetic resonance identified the purified toxin as 7 beta-hydroperoxycholest-5-en-3 beta ol (7 beta-OOH-Chol). This molecule accounted for approximately 90% of the cytotoxicity of the lipids of oxidized LDL. We also found 7-beta-OOH-Chol in human atherosclerotic lesions from endarterectomy specimens obtained immediately after excision. These results are consistent with the hypothesis that the oxidized LDL present in lesions has the capacity to induce cell and tissue injury, leading to progression of the disease and the generation of the necrotic core of the lesion.

Disease outbreaks with high mortality rates among seals and dolphins have recently attracted considerable public and scientific interest. Although in most cases morbilli-virus infections were shown to be the primary cause of the disease outbreaks, it was speculated that pollution-induced immunosuppression had played a contributory role. Here we present results of a prospective study under semifield conditions, in which two groups of harbor seals (Phoca vitulina) were fed herring from marine regions with different contamination levels; the highly polluted Baltic Sea and the relatively unpolluted Atlantic Ocean. During a period of 93 weeks, parameters related to immune function were monitored and compared between the two groups. We found that natural killer-cell activity and mitogen-induced proliferative T-cell responses from the seals feeding on herring from the Baltic Sea were significantly lower. In addition, we observed higher levels of circulating polymorphonuclear granulocytes in these animals, which may indicate an increase in the occurrence of bacterial infections. This is the first demonstration of impaired immunological functions in mammals associated with chronic exposure to environmental contaminants accumulated through the marine food chain.