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11.
Consumption of plants of the species Brassica oleracea is related to a decreased incidence of certain cancer forms in humans, and this has been linked to the presence of glucosinolates in those vegetables. After ripe seeds, sprouts of some brassicaceous plants contain the highest concentration of these compounds and are therefore a good source of glucosinolates for chemoprotection. In the present experiments, the content and distribution of glucosinolates was determined in ripe seeds and sprouts (seedlings) of five varieties of B. oleracea (white cabbage, red cabbage, Savoy cabbage, broccoli and cauliflower) by high performance liquid chromatography. The type and concentration of individual glucosinolates varied according to variety of B. oleracea, plant parts in which they occurred and the sprouting period of the seed. Concentration of alkyl glucosinolates decreased whereas that of indol-3-ylmethylglucosinolates increased throughout the sprouting period. Roots had the highest glucosinolate concentration in four and seven day old sprouts whereas at both sprouting times, cotyledons had the highest concentration of alkylthio- and alkylsulphinylglucosinolates.  相似文献   
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Uptake and leakage experiments were performed to study the effects of copper and cadmium on K(+) fluxes in birch (Betula pendula Roth) roots. Labeled rubidium ((86)Rb(+)) was used as a tracer for K(+). Plants were pretreated with Cu or Cd (0, 2, 5 or 25 microM) for 0-300 min and then transferred to radiolabeled nutrient solution (150 microM K(+)) with or without 2,4-dinitrophenol (DNP) to separate the effects of heavy metal on active and passive K(+) influxes. Passive K(+) influx was decreased by pretreatment with Cu but was only slightly affected by pretreatment with Cd. Pretreatment with 2 microM Cu increased active K(+) influx, whereas pretreatment with 25 microM Cu decreased active K(+) influx and intermediate Cu concentrations (5 microM) did not affect active K(+) influx. The pretreatment effects of Cu on active and passive K(+) influxes increased with increasing pretreatment time. During the first hour, pretreatment with Cd decreased active K(+) influx with increasing pretreatment time, whereafter recovery began. To measure K(+) efflux, birch plants were loaded with (86)Rb(+) for 7 days before being exposed to Cu or Cd (0, 1, 3, 5 or 10 microM) in unlabeled nutrient solutions for 24 h. Net efflux of K(+) was measured as (86)Rb(+)-activity in the nutrient solutions 24 h after a heavy metal had been introduced. Efflux of K(+) increased with increasing Cu or Cd concentration in the unlabeled nutrient solution.The data indicate that Cu and Cd affected K(+) influx differently and that recovery mechanism(s), which were induced shortly after heavy metal introduction, counteracted the heavy-metal induced inhibition of active K(+) influx. Efflux of K(+) from plant roots over a 24-h period indicated that Cu and Cd had similar effects on K(+) efflux. There was no evidence of a recovery mechanism counteracting the heavy-metal-induced inhibition of K(+) efflux.  相似文献   
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15.
A novel HPLC method was developed for detection of the Fusarium mycotoxin, moniliformin in whole maize plants. The method is based on hydrophilic interaction chromatography (HILIC) on a ZIC zwitterion column combined with diode array detection and negative electrospray mass spectrometry (ESI(-)-MS). Samples were extracted using acetonitrile-water (85:15), and the extracts were cleaned up on strong anion exchange columns. By this procedure we obtained a recovery rate of 57-74% moniliformin with a limit of detection at 48 ng/g and a limit of quantification at 96 ng/g using UV detection at 229 nm, which is comparable to current methods used. Limit of detection and quantification using ESI(-)-MS detection was 1 and 12 ng/g, respectively. Screening of maize samples infected with the moniliformin producing fungi F. avenaceum, F. tricinctum, or F. subglutinans detected moniliformin levels of 1-12 ng/g in 15 of 28 samples using ESI(-)-MS detection. To our knowledge this is the first example of HILIC separation in mycotoxin analysis.  相似文献   
16.
Foot-and-mouth disease (FMD) is a highly contagious aphthoviral infection of cloven-hoofed animals, inducing vesiculopustular stomatitis, pododermatitis, and thelitis. Vesicular fluid represents a major pathway of virus excretion, but bovine milk is another important source of virus shedding. We describe here the time course of FMD virus (FMDV) excretion in the milk and characterize associated lesions in the mammary gland. Three dairy cows were infected by nasopharyngeal instillation of FMDV and monitored over 12 d. Autopsy was performed at the end of the study, and specimens were collected for histopathology, IHC, and RT-qPCR. All 3 cows developed fever, drooling, vesiculopustular stomatitis, interdigital dermatitis, and thelitis. FMDV RNA was detectable in whole milk until the end of the trial, but only transiently in saliva, nasal secretions, and blood serum. Although histology confirmed vesiculopustular lesions in the oral and epidermal specimens, the mammary glands did not have unequivocal evidence of FMDV-induced inflammation. FMDV antigen was detectable in skin and oral mucosa, but not in the mammary gland, and FMDV RNA was detectable in 9 of 29 samples of squamous epithelia but only in 1 of 12 samples of mammary gland.  相似文献   
17.
Skin lesions on pigs inflicted by humans compromise animal welfare and are the subject of increased public and political attention in Denmark. Systematic surveillance of such skin lesions was enforced in April 2010 at all Danish pig abattoirs, through the recording of meat inspection Code 904 for the presence of skin lesions suspected to be human inflicted. The objectives of the present study were to (a) estimate the apparent prevalence of Code 904s at the pig and herd owner level; (b) characterise the distribution of deliveries with pigs demonstrating a Code 904; (c) characterise the distribution of herd owners with repeated Code 904 recordings; and (d) determine the developments in Code 904 prevalence over time in Danish finishing pigs in the period from May 1, 2010 to September 30, 2013.  相似文献   
18.
Antibodies to Coxiella burnetii have been found in the Danish dairy cattle population with high levels of herd and within herd seroprevalences. However, the prevalence of antibodies to C. burnetii in Danish beef cattle remains unknown. The objectives of this study were to (1) estimate the prevalence and (2) identify risk factors associated with C. burnetii seropositivity in Danish beef and dairy cattle based on sampling at slaughter.  相似文献   
19.

Background

The major indication for antibiotic use in Danish pigs is treatment of intestinal diseases post weaning. Clinical decisions on antibiotic batch medication are often based on inspection of diarrhoeic pools on the pen floor. In some of these treated diarrhoea outbreaks, intestinal pathogens can only be demonstrated in a small number of pigs within the treated group (low pathogen diarrhoea). Termination of antibiotic batch medication in herds suffering from such diarrhoea could potentially reduce the consumption of antibiotics in the pig industry. The objective of the present pilot study was to suggest criteria for herd diagnosis of low pathogen diarrhoea in growing pigs.Data previously collected from 20 Danish herds were used to create a case series of clinical diarrhoea outbreaks normally subjected to antibiotic treatment. In the present study, these diarrhoea outbreaks were classified as low pathogen (<15% of the pigs having bacterial intestinal disease) (n =5 outbreaks) or high pathogen (≥15% of the pigs having bacterial intestinal disease) (n =15 outbreaks). Based on the case series, different diagnostic procedures were explored, and criteria for herd diagnosis of low pathogen diarrhoea were suggested. The effect of sampling variation was explored by simulation.

Results

The diagnostic procedure with the highest combined herd-level sensitivity and specificity was qPCR testing of a pooled sample containing 20 randomly selected faecal samples. The criteria for a positive test result (high pathogen diarrhoea outbreak) were an average of 1.5 diarrhoeic faecal pools on the floor of each pen in the room under investigation and a pathogenic bacterial load ≥35,000 per gram in the faecal pool tested by qPCR. The bacterial load was the sum of Lawsonia intracellularis, Brachyspira pilosicoli and Escherichia coli F4 and F18 bacteria per gram faeces. The herd-diagnostic performance was (herd-level) diagnostic sensitivity =0.99, diagnostic specificity =0.80, positive predictive value =0.94 and negative predictive value =0.96.

Conclusions

The pilot study suggests criteria for herd diagnosis of low pathogen diarrhoea in growing pigs. The suggested criteria should now be evaluated, and the effect of terminating antibiotic batch medication in herds identified as suffering from low pathogen diarrhoea should be explored.

Electronic supplementary material

The online version of this article (doi:10.1186/2046-0481-67-24) contains supplementary material, which is available to authorized users.  相似文献   
20.
The mechanisms underlying the social structure of free‐ranging fish shoals have received little attention in comparison to functional studies on shoaling. Recently, however, a number of investigations, both in the marine and in the freshwater environment, have begun to address the underlying mechanisms by concentrating on interactions between free‐ranging shoals. The rates of shoal encounters can influence the opportunities for individual assortment by phenotype and selection of shoal size; act as a constraint on the observed patterns of shoal structure by restricting individual choice behaviour and were found to be high in several small freshwater species (where intershoal distances were small), but lower in marine species where shoals were more dispersed. The duration of encounters may play a role in that it affects both the time available for assessment (of the encountered shoal) as well as that for exchange of individuals. Scarce published information on the outcome of shoal encounters suggests that the outcome of shoal encounters is influenced by shoal composition but not by shoal size. Individual behaviour may have evolved to maintain shoal size when shoals encounter, but when fish populations are depleted by fishing, this trait can exacerbate range and stock collapse. Furthermore, an understanding of the dynamics of shoal encounters has important consequences for the evolution of reciprocal altruism and the transmission of information through social learning within populations. Finally, information on encounter rates between shoals and the number of individuals that are exchanged on such occasions could be important for making predictions about the spread of disease through fish populations.  相似文献   
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