Liposome-entrapped superoxide dismutase reduces ischemia/reperfusion ‘oxidative stress’ in gerbil brain

Bilateral common carotid artery occlusion (15 min.) followed by two hours of recirculation reduced mitochondrial superoxide dismutase (SOD) and glutathione reductase (GR) activities, and increased susceptibility of mitochondrial membranes to in vitro lipid peroxidation in brain regions (i.e., cortex, striatum and hippocampus) of Mongolian gerbil. Intraperitoneal bolus injection (2 mg/kg b.w.) of liposome-entrapped CuZn superoxide dismutase (l-SOD) increased the endogenous SOD activity in normal brain tissue and, when given at the end of ischemia, counteracted both the ischemic reduction of endogenous SOD and the increased peroxidation of mitochondrial membranes. 1-SOD treatment was ineffective in reducing brain swelling, suggesting that superoxide radicals are not a main participant in the process of (post)ischemic brain edema formation.     

Molecular and allergenic characterization of recombinant tropomyosin from mud crab Scylla olivacea

Molecular Biology Reports - Tropomyosin is a major allergen in crustaceans, including mud crab species, but its molecular and allergenic properties in Scylla olivacea are not well known. Thus, this...     

Phylogeny and classification of Leptophlebiidae (Ephemeroptera) with an emphasis on Neotropical fauna

Mayflies from the family Leptophlebiidae are cosmopolitan and highly diverse morphologically; they are also the largest family in numbers of genera and the second in number of species in the order Ephemeroptera. In spite of their broad diversity and the efforts employed to understand the evolution of this group, the internal classification of Leptophlebiidae remains controversial at all levels. More recently, important changes have been incorporated into the systematics of the family, increasing the number of subfamilies (from two to six) and recognizing several tribes. We present a phylogeny of the family based on 153 taxa (53 genera) and two molecular markers, representing 1655 bp, and verify the taxonomic status of the subfamilies, tribes and complexes. Based on these results, the number of subfamilies has been increased from six to eight and one new tribes and two new subtribes have been added. In addition, new ranks are proposed and the concept of Atalophlebiinae revised, including genera with distributions in the Australasian and Neotropical regions.     

Do foliar endophytes affect grass litter decomposition? A microcosm approach using Lolium multiflorum

Symbiotic infection with fungal endophytes has been shown to decrease herbivory in several temperate grasses. We tested the hypothesis that foliar endophytes of grasses may also affect below-ground processes upon their host death, by altering the litter quality for detritivores or the microenvironment for decomposition. Microcosm–litterbag experiments were used to assess decay rates for litter produced by endophyte ( Neotyphodium sp.) infected vs uninfected Lolium multiflorum plants, and to examine endophyte-mediated effects of prior site occupants on current litter decomposition. We found that litter from endophyte-infected L. multiflorum decomposed more slowly than litter from endophyte-free conspecifics and from a naturally uninfected grass, Bromus unioloides . Furthermore, the endophyte–grass association modified the decomposition environment, so that B. unioloides litter decomposed faster when placed underneath a thick layer of endophyte-free L. multiflorum litter. Litter decay rates increased with the amount of root debris remaining in situ from the previous season, but were not affected by the infection status of prior site occupants. The lower decomposability of litter from infected L. multiflorum plants persisted across a range of microenvironments, as determined by different amounts of above-ground litter and soil moisture conditions. Endophyte infection tended to reduce the N content of decaying litter; however, litter N and C/N ratio mainly accounted for interspecific differences in decomposition. Our results imply that fungal endophytes not only can affect herbivory food chains, but also soil organisms and the ecosystem processes they regulate. This study suggests a novel role for symbiotic foliar endophytes in linking above-ground and below-ground sub-systems.     

Status of nutrition and health claims in Europe

Functional foods are closely associated with claims on foods. There are two categories of claims on foods: nutrition claims and health claims. Health claims on (functional) foods must be scientifically substantiated. In December 2006, the European Union published its Regulation 1924/2006 on nutrition and health claims made on foods. As concerns scientific evaluation, the EU-project PASSCLAIM resulted in a set of criteria for the scientific substantiation of health claims on foods. The European Food Safety Authority provides the scientific advise to the European Commission for health claims submitted under Regulation 1924/2006 and has hitherto published several hundreds of opinions on health claims, part of which are positive, part which are negative and a few with insufficient evidence. Antioxidant claims have been approved for the general function of vitamins but not for direct health effects in humans. Another issue with claims is consumer understanding. Consumers can hardly distinguish between graded levels of evidence, and they do make only little or no distinction between nutrition and health claims. Consumers understand nutrition and health claims different from scientists and regulators. Therefore, innovation in industry can readily proceed via approved nutrition claims and approved health claims. The market and the shelves in the stores will not be empty; rather they will look different in the years to come.     

Development of the digestive system of Argentine hake,Merluccius hubbsi,larvae

The Argentine hake Merluccius hubbsi is an important fishery resource of the Southwestern Atlantic Ocean and it is also a potential species for cultivation. In this work, the digestive system development in field-caught hake larvae was studied using histological and histochemical approaches. The digestive tract of larvae was divided into: oropharyngeal cavity (OPC), esophagus, stomach (that develops in the preflexion stage), and intestine. The annexed digestive glands consisted of the liver and the exocrine pancreas. At the beginning of the preflexion stage, teeth were developed in the OPC. There were mucous cells in the esophagus secreting different glycoconjugates from hatching. The enterocytes in the posterior intestine exhibited supranuclear vesicles associated with protein absorption. Mucous cells were observed in the posterior intestine in the preflexion stage and, in the anterior region, ending the flexion stage. Each type of glycoconjugates has a specific role. Acidic mucins lubricate and protect from mechanical damage, sialomucines protect from bacterial infections and neutral mucins regulate the acidity of mucus secretion, protect against abrasion and participate in the formation of the chyme, indicating a pregastric digestion. The liver was present since hatching with pancreatic tissue inside and increased in size acquiring the typical structure with hepatocyte cords, sinusoids, vacuoles, and hepatic duct. The hepatocytes vacuolization increased with larval development. The pancreas became extra-hepatic, with basophilic acinar cells and acidophilic zymogen granules. Throughout the ontogeny, the increased structural and functional complexity of the digestive system reflected the transition to exogenous feeding and nutritional increasing needs.