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991.
Martins HM Almeida IF Camacho CR Santos SM Costa JM Bernardo FM 《Revista iberoamericana de micología》2012,29(3):175-177
BackgroundFumonisin B1 (FB1), fumonisin B2 (FB2), and overall mycotoxins feed contamination may cause several effects on crops production and animal health. The contamination occurred predominantly in corn and corn-based foods and feeds.AimsThis survey intends to provide the occurrence of fumonisins in swine and equine mixed feeds in Portugal, making an overview from 2007 to 2010.MethodsA total of 363 samples were analyzed, 258 from swine feed and 105 from horse feed with HPLC method. The detection limit was 50 μg/kg for FB1 and 100 μg/kg for FB2.ResultsThe overall results were 13% of FB1 occurrence from 2007 to 2010. FB1 was detected in about 17.0% of swine feed samples, being more frequent in 2010 (32.9%). In this year (2010) levels ranged between 66.7 and 3815.5 μg/kg.FB2 occurred only in 2010 in swine feed (6 samples, ranging between 104.0 to 467.2 μg/kg) and in horse feed (1 sample).ConclusionsThis represents an increase in occurrence through the analyzed years, but this may not be a threat to animal health, once the values were below the recommended guidance values from European Commission. 相似文献
992.
BackgroundFour biopesticide prototypes formulated as dispersible granules and dry powders based on 2 Colombian isolates of Trichoderma koningiopsis (Th003) and T. asperellum (Th034) were developed. These microorganisms have antagonist activity against Fusarium oxysporum f. sp. lycopersici and Rhizoctonia solani with a reduction in incidence of between 70 and 100% in tomato crops and potato crops, respectively.AimTo determine the effect of the formulation on the shelf-life of 4 biopesticides based on T. koningiopsis Th003 and Trichoderma asperellum Th034 at 3 different temperatures.MethodsThe formulation effect was determined by evaluating the germination of unformulated and formulated conidia (dispersible granules and dry powder) stored at 8, 18 and 28 °C for 18 months. Germination kinetics were used to estimate the shelf-life by using different mathematical models (zero order, first order, second order, Higuchi model, Korsmeyer-Peppas model and polynomial model).ResultsThe products showed high stability of the conidia germination when they were stored at 8 and 18° C, with shelf-lives of 14.4 and 13.9 months for dry powder based on Th003, and 12.0 and 10.8 months for dry powder based on Th034, respectively. Prototypes formulated as dispersible granules stored at the same temperatures (8 and 18 °C) showed lower shelf-lives, with values of 11.6 and 10.9 months for the Th003 product, and 10.7 and 7.2 months for the dispersible granules based on Th034. Significant reductions in germination were observed on unformulated conidia at all storage temperatures evaluated.ConclusionsThe formulation type affected the conidia stability of the 2 Trichoderma spp. Colombian isolates. Dry powder was the prototype with the highest stability and shelf-life at all temperatures evaluated. 相似文献
993.
Kleiton Augusto dos Santos Silva Rafael da Silva Luiz Rodolfo Rosseto Rampaso Nayda Parísio de Abreu édson Dias Moreira Cristiano Teixeira Mostarda Kátia De Angelis Vicente de Paulo Castro Teixeira Maria Cláudia Irigoyen Nestor Schor 《PloS one》2012,7(11)
Exercise training (ET) is an important intervention for chronic diseases such as diabetes mellitus (DM). However, it is not known whether previous exercise training intervention alters the physiological and medical complications of these diseases. We investigated the effects of previous ET on the progression of renal disease and cardiovascular autonomic control in rats with streptozotocin (STZ)-induced DM. Male Wistar rats were divided into five groups. All groups were followed for 15 weeks. Trained control and trained diabetic rats underwent 10 weeks of exercise training, whereas previously trained diabetic rats underwent 14 weeks of exercise training. Renal function, proteinuria, renal sympathetic nerve activity (RSNA) and the echocardiographic parameters autonomic modulation and baroreflex sensitivity (BRS) were evaluated. In the previously trained group, the urinary albumin/creatinine ratio was reduced compared with the sedentary diabetic and trained diabetic groups (p<0.05). Additionally, RSNA was normalized in the trained diabetic and previously trained diabetic animals (p<0.05). The ejection fraction was increased in the previously trained diabetic animals compared with the diabetic and trained diabetic groups (p<0.05), and the myocardial performance index was improved in the previously trained diabetic group compared with the diabetic and trained diabetic groups (p<0.05). In addition, the previously trained rats had improved heart rate variability and BRS in the tachycardic response and bradycardic response in relation to the diabetic group (p<0.05). This study demonstrates that previous ET improves the functional damage that affects DM. Additionally, our findings suggest that the development of renal and cardiac dysfunction can be minimized by 4 weeks of ET before the induction of DM by STZ. 相似文献
994.
995.
The middle section of the lake basin of the Doce River in Minas Gerais State, Brazil is plagued by grave environmental problems, including the introduction of non-native fish, which reduces the biodiversity of this region. This study reports the presence of two newly-detected non-native species in the Doce River Basin. Sampling efforts included gill nets with mesh size of 3 to 12 mm (measured diagonally) and trawling nets, both of which were used in independent field campaigns in 2002 and 2011. The two new invasive Perciform fishes, Plagioscion squamosissimus (Heckel 1840) and Parachromis managuensis (Günther 1867) were collected in Caratinga and Rio Doce municipalities. These records and other reports on non-native fishes suggest favorable environmental conditions for the establishment of invasive species in this drainage. These invasive species have behavior and diet observed in other wide distribution exotic fish of Rio Doce Basin representing a threat to the 77 native fishes of this region, 37 of which are endangered. 相似文献
996.
Dramatic population declines among species of pelagic shark as a result of overfishing have been reported, with some species now at a fraction of their historical biomass. Advanced telemetry techniques enable tracking of spatial dynamics and behaviour, providing fundamental information on habitat preferences of threatened species to aid conservation. We tracked movements of the highest pelagic fisheries by-catch species, the blue shark Prionace glauca, in the North-east Atlantic using pop-off satellite-linked archival tags to determine the degree of space use linked to habitat and to examine vertical niche. Overall, blue sharks moved south-west of tagging sites (English Channel; southern Portugal), exhibiting pronounced site fidelity correlated with localized productive frontal areas, with estimated space-use patterns being significantly different from that of random walks. Tracked female sharks displayed behavioural variability in diel depth preferences, both within and between individuals. Diel depth use ranged from normal DVM (nDVM; dawn descent, dusk ascent), to reverse DVM (rDVM; dawn ascent, dusk descent), to behavioural patterns where no diel differences were apparent. Results showed that blue sharks occupy some of the most productive marine zones for extended periods and structure diel activity patterns across multiple spatio-temporal scales in response to particular habitat types. In so doing, sharks occupied an extraordinarily broad vertical depth range for their size (1.0-2.0 m fork length), from the surface into the bathypelagic realm (max. dive depth, 1160 m). The space-use patterns of blue sharks indicated they spend much of the time in areas where pelagic longlining activities are often highest, and in depth zones where these fisheries particularly target other species, which could account for the rapid declines recently reported for blue sharks in many parts of the world's oceans. Our results provide habitat targets for blue shark conservation that may also be relevant to other pelagic species. 相似文献
997.
The 5-phospho-α-D-ribose 1-diphosphate (PRPP) metabolite plays essential roles in several biosynthetic pathways, including histidine, tryptophan, nucleotides, and, in mycobacteria, cell wall precursors. PRPP is synthesized from α-D-ribose 5-phosphate (R5P) and ATP by the Mycobacterium tuberculosis prsA gene product, phosphoribosylpyrophosphate synthase (MtPRS). Here, we report amplification, cloning, expression and purification of wild-type MtPRS. Glutaraldehyde cross-linking results suggest that MtPRS predominates as a hexamer, presenting varied oligomeric states due to distinct ligand binding. MtPRS activity measurements were carried out by a novel coupled continuous spectrophotometric assay. MtPRS enzyme activity could be detected in the absence of P(i). ADP, GDP and UMP inhibit MtPRS activity. Steady-state kinetics results indicate that MtPRS has broad substrate specificity, being able to accept ATP, GTP, CTP, and UTP as diphosphoryl group donors. Fluorescence spectroscopy data suggest that the enzyme mechanism for purine diphosphoryl donors follows a random order of substrate addition, and for pyrimidine diphosphoryl donors follows an ordered mechanism of substrate addition in which R5P binds first to free enzyme. An ordered mechanism for product dissociation is followed by MtPRS, in which PRPP is the first product to be released followed by the nucleoside monophosphate products to yield free enzyme for the next round of catalysis. The broad specificity for diphosphoryl group donors and detection of enzyme activity in the absence of P(i) would suggest that MtPRS belongs to Class II PRS proteins. On the other hand, the hexameric quaternary structure and allosteric ADP inhibition would place MtPRS in Class I PRSs. Further data are needed to classify MtPRS as belonging to a particular family of PRS proteins. The data here presented should help augment our understanding of MtPRS mode of action. Current efforts are toward experimental structure determination of MtPRS to provide a solid foundation for the rational design of specific inhibitors of this enzyme. 相似文献
998.
999.
A Weingärtner G Kemmer FD Müller RA Zampieri M Gonzaga Dos Santos J Schiller TG Pomorski 《PloS one》2012,7(8):e42070
The protozoan parasite Leishmania is an intracellular pathogen infecting and replicating inside vertebrate host macrophages. A recent model suggests that promastigote and amastigote forms of the parasite mimic mammalian apoptotic cells by exposing phosphatidylserine (PS) at the cell surface to trigger their phagocytic uptake into host macrophages. PS presentation at the cell surface is typically analyzed using fluorescence-labeled annexin V. Here we show that Leishmania promastigotes can be stained by fluorescence-labeled annexin V upon permeabilization or miltefosine treatment. However, combined lipid analysis by thin-layer chromatography, mass spectrometry and (31)P nuclear magnetic resonance (NMR) spectroscopy revealed that Leishmania promastigotes lack any detectable amount of PS. Instead, we identified several other phospholipid classes such phosphatidic acid, phosphatidylethanolamine; phosphatidylglycerol and phosphatidylinositol as candidate lipids enabling annexin V staining. 相似文献
1000.
Guido Lopes dos Santos Santiago Inge Tency Hans Verstraelen Rita Verhelst Marijke Trog Marleen Temmerman Leen Vancoillie Ellen Decat Piet Cools Mario Vaneechoutte 《PloS one》2012,7(9)