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991.
Abstract

Deoxynivalenol (DON) produces two characteristic toxicological effects, decreased feed consumption (anorexia) and emesis. Both effects have been linked to increased central (CNS) serotoninergic activity. Although there has also been some indication of a peripheral involvement, the role of blood pools of serotonin and related compounds in mediating DON toxicity is not well defined. In this study, the effect of DON on plasma concentrations of serotonin (5‐hydroxytryptamine, 5HT), 5HIAA (5‐hydroxyindoleacetic acid) and tryptophan (TRP), as a reflection of an induced peripheral serotoninergic system, was investigated in swine.

Typical values for the plasma concentrations of 5HT, 5HIAA, and TRP were established in pigs. Following administration of DON, either intragastrically or intravenously, concentration changes in these substances were measured over an eight hour period. The effect of low and high toxin doses were also compared.

Analyses showed no effect on plasma levels of the compounds of interest, even at sufficient toxin doses to invoke emesis in the test animals. Any variation over the course of the study remained within acceptable control limits. These results indicated no peripheral effect by DON which could account for the increased serotoninergic activity associated with altered feeding behaviour or emesis.  相似文献   
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997.
Risk factors for driving into flooded roads   总被引:2,自引:0,他引:2  
Motor vehicle-related deaths account for more than half of all flood fatalities in the United States, but to date, very little is known about the risk factors associated with why people drive into flooded roads. Using data from survey questionnaires administered in Denver, CO, and Austin, TX, this paper suggests that people who do not take warnings seriously are more likely to drive through flooded roads, as are people aged 18–35, and those that do not know that motor vehicles are involved in more than half of all flood fatalities. In Denver, people who have not experienced a flood previously and those who do not know they live in flood-prone areas are also more likely to drive into flooded roads.  相似文献   
998.
The population structure and biological parameters of the European whitefish, Coregonus lavaretus (L.), have been analyzed in a technogenically polluted water body. The biochemical state of the whitefish and the fauna and morphology of helminths parasitizing them have been assessed. It is shown that the species composition of the fish, plankton, benthos, and parasite faunas of this water body are depleted and the morphological parameters of common fish parasites are altered. It is noted that, in addition to adaptive rearrangements in biochemical metabolism, the whitefish from the transformed water body are characterized by a reduction in the level of protein synthesis in muscles and the rate of aerobic energy metabolism in the liver and muscles.  相似文献   
999.
Nutrient enrichment of the seafloor (benthos) has been a primary subject of investigation since the beginning of commercial salmon farming. Waste feed and feces passing through the containment nets can create zones of organic enrichment to the benthos in the vicinity of the pen cages. Early studies of salmon farming in British Columbia Canada (500–1200 metric ton production farms) showed that these effects varied greatly and were reduced where conditions of adequate water depth and strong tidal currents were present. More recent studies of farms producing in excess of 2000 tons of fish have documented measurable organic benthic impacts.The implementation of a performance-based waste regulation in British Columbia in 2002 has caused operational changes to achieve and maintain compliance. This paper describes field monitoring data for four representative farm operations including the waste impact levels prior to the implementation of regulatory standards and the effect of adaptive management actions taken to reduce organic enrichment such as modified feed delivery, relatively small position changes to the cages or reducing site production to achieve continuing compliance.Monitoring over several full production cycles at selected farms indicated that sediment impacts at maximum production levels have decreased while maintaining, and in some cases increasing overall production of salmon.  相似文献   
1000.
Congenital heart defects (CHDs) are associated with neurodevelopmental (ND) delay. This study aims to assess evidence for impaired prenatal brain development, in fetuses with CHD. A systematical search was performed, and 34 studies evaluating the fetal brain [magnetic resonance imaging (MRI) or ultrasound] in isolated CHD were included (1990–2015). Data regarding cerebral abnormalities, head circumference growth and middle cerebral artery flow were extracted. Prenatal MRI was studied in ten articles (445 fetuses), resulting in a pooled prevalence of 18% (95%CI −6%; 42%) for combined structural and acquired cerebral abnormalities. Prenatal head circumference was studied in 13 articles (753 fetuses), resulting in a pooled z-score of −0.51 (95%CI −0.84; −0.18). Doppler was studied in 21 articles (1412 fetuses), resulting in a lower middle cerebral artery pulsatility index (z-score −0.70 95%CI −0.99; −0.41) in left-sided CHD only. We conclude that prenatal MRI and ultrasound demonstrate brain abnormalities, delay in head growth and brainsparing in subgroups of CHD. However, large MRI studies are scarce, and ultrasound data are biased towards severe and left-sided CHD. Long-term follow-up studies correlating prenatal findings with postnatal ND outcome are limited, and data are lacking to support counseling families regarding ND outcome based on prenatal findings suggestive of altered brain development. © 2016 John Wiley & Sons, Ltd.  相似文献   
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