52 research outputs found

    Eyestalk ligation experiments on the fairy shrimp Streptocephalus dichotomus

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    The endocrine system of lower crustaceans such as anostracan also shows a similarity with that of decapod crustaceans, especially in the possession of a stalked eye in which is present the X-organ sinus gland complex (Lake, 1969). In the fairy shrimp Streptocephalus dichotomus, the sinus gland is located inbetween the lamina ganglionaris and the optic medulla. The cells in this gland show variation in their secretory contents during reproductively quiescent and reproductively active period

    Fertilization and early development in the polychaete Hydroides lunulifera

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    The eggs of the marine polychaete Hydroides lunulifera are small and their fertilization is external. This animal is suitable for experimental studies due to a number of features such as the ease with which the sperms and eggs could be obtained, the prolonged breeding season and the relatively simple conditions under which fertilization and development are accomplished in the laboratory conditions

    Protective responses of antioxidant enzymes against bisphenol-A induced oxidative stress in Asian Seabass Lates calcarifer

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    1458-1463Bisphenol A (BPA) is an endocrine disruptor used as plastic monomer and plasticizer widely present in the aquatic environment. In the present study, the effect of BPA on the antioxidant system in Lates calcarifer was documented. Three different concentrations such as 1, 10, 100 µg/l were selected and exposed to fishes for 30 days. After BPA exposure, antioxidant parameters were estimated against control. The levels of marker enzymes were assessed in the gill, muscle, liver and brain tissues. The results showed that the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and lipid peroxidation (LPx) were increased in treated groups than control. On the other hand, reduced glutathione (GSH) level was decreased in BPA exposed groups compared to control. Based on the results, imbalance in the antioxidant defence system clearly indicated that the BPA toxicity could lead to susceptible oxidative stress in various tissues of the fish L. calcarifer

    Transcellular communication at the immunological synapse: A vesicular traffic-mediated mutual exchange

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    The cell's ability to communicate with the extracellular environment, with other cells, and with itself is a crucial feature of eukaryotic organisms. In the immune system, T lymphocytes assemble a specialized structure upon contact with antigen-presenting cells bearing a peptide-major histocompatibility complex ligand, known as the immunological synapse (IS). The IS has been extensively characterized as a signaling platform essential for T-cell activation. Moreover, emerging evidence identifies the IS as a device for vesicular traffic-mediated cell-to-cell communication as well as an active release site of soluble molecules. Here, we will review recent advances in the role of vesicular trafficking in IS assembly and focused secretion of microvesicles at the synaptic area in naïve T cells and discuss the role of the IS in transcellular communication

    Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial

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    Background Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects. Methods FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762. Findings Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839–1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26–6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38–2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months. Interpretation Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function. Funding UK Stroke Association and NIHR Health Technology Assessment Programme

    Induction of population growth, mictic fernale production and resting eggs formation by treatment of GnRh analogue in the freshwater rotifer Brachinous Calyciflorus Pallas

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    Enriched commercial and artificial diets are unsuitable for the post larval stages of various commercially important crustacea and fish, which require live foods (such as rotifers, brine shrimp or fairy shrimp). The larger size of the brine shrimp and fairy shrimp make them unsuitable for larval fish and shrimp requiring small zooplanktons such as rotifers, as their initial diet. This study was designed to develop a reliable technique for inducing population growth, mictic female production and body size in the freshwater rotifer, Brachionus calyciflorus by treatment with the synthetic hormone Ovaprim. Ovaprim is a synthetic GnRH analogue with domperidone. Concentrations of Ovaprim from 0.05, 0.5, 5 and 50 μl ml−1 were added to Chlorella vulgaris suspension (2×106 cells ml−1). Population growth significantly increased in treatments exposed to 0.05 and 0.5 μl ml−1 while higher mortality was observed at the concentrations of 50 and 5 μl ml−1. Ovaprim had no effect on mictic female production and hence also on the resting egg production. Lorica length increased to 19.47 and 19.16 μm in rotifers treated with 0.5 and 0.05 μl ml−1 hormone concentrations and decrease in lorica length was observed at 50 and 5 μl ml−1 concentrations (13.44 and 15.17 μm). Increase in the lorica width (13.41 μm) was observed on treatment with 0.5 μl ml−1 concentration of Ovaprim when compared to the control. The results of the experiment suggest that Ovaprim treatment at 0.5 μl ml−1 concentration have significant modulatory effects on the population growth, mictic female production and body size of B. calyciflorus

    Interpopulation study of three Artemia

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    Not AvailableThe endocrine system of lower crustaceans such as anostracan also shows a similarity with that of decapod crustaceans, especially in the possession of a stalked eye in which is present the X-organ sinus gland complex (Lake, 1969). In the fairy shrimp Streptocephalus dichotomus, the sinus gland is located inbetween the lamina ganglionaris and the optic medulla. The cells in this gland show variation in their secretory contents during reproductively quiescent and reproductively active periodsNot Availabl

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    Not AvailableThe eggs of the marine polychaete Hydroides lunulifera are small and their fertilization is external. This animal is suitable for experimental studies due to a number of features such as the ease with which the sperms and eggs could be obtained, the prolonged breeding season and the relatively simple conditions under which fertilization and development are accomplished in the laboratory conditions.Not Availabl
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