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Coetzee JF Schmidt PL Apley MD Reinbold JB Kocan KM 《American journal of veterinary research》2007,68(8):872-878
OBJECTIVE: To compare sensitivity of a complement fixation (CF) test and competitive ELISA (cELISA) for detection of Anaplasma marginale in experimentally infected steers. ANIMALS: 40 crossbred (Angus-Simmental) steers. PROCEDURES: Steers were inoculated with 2.6 x 10(9) A marginale-infected erythrocytes (day 0). Blood samples were collected on days 9, 13, 20, 28, 34, 41, 61, 96, 126, and 156 days after inoculation. The percentage of parasitized erythrocytes (PPE) was determined by microscopic examination of stained blood films, and sera were evaluated with the CF test and cELISA by use of USDA-approved methods. Sensitivity and agreement (kappa statistic) between the 2 methods were determined. Persistent infections were confirmed by inoculation of blood obtained from infected steers into susceptible, splenectomized calves. RESULTS: 9 days after inoculation, sensitivity of the cELISA was 47.5%, whereas the CF test failed to identify seropositive steers. After day 13, sensitivity of the cELISA and CF test was 100% and 20%, respectively. During peak parasitemia (day 20), sensitivity of the cELISA and CF test was 100%. Thereafter, sensitivity of the CF test fluctuated between 7.5% and 37.5%, whereas sensitivity of the cELISA remained at 100%. Overall sensitivity of the cELISA and CF test was 94.8% and 26.5%, respectively (kappa statistic, 0.039). CONCLUSIONS AND CLINICAL RELEVANCE: The cELISA had superior sensitivity for serologic detection of A marginale.The CF test and cELISA each had a high percentage of false-negative results during the prepatent period. These findings are relevant for export certification and anaplasmosis prevention or eradication programs. 相似文献
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Enterohemorrhagic Escherichia coli (EHEC) are a subgroup of Shiga toxin-producing Escherichia coli (STEC) that are able to cause serious food-borne intestinal diseases which can be followed in 5 to 15% by extraintestinal sequelae such as the hemolytic-uremic syndrome (HUS). One of the major pathogenicity factors of EHEC is the production of one or more Shiga toxins (Stx), which act as inhibitors of protein biosynthesis and have profound effects on the signal transduction and immunological response in eukaryotic cells. The stx genes are located in the genome of heterogeneous, lambdoid, functional or cryptic bacteriophages and are expressed during the phage life cycle. Due to the linkage between the phage life cycle and stx expression, STEC and their bacteriophages are useful as a model for the analysis of stress response and virulence of this food-borne pathogen. 相似文献
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The porcine immune system differs in many aspects from that of humans and mice. Morphological differences in the lymphatic system (e.g. lymph nodes, Peyer's patches), and phenotypic differences in immune cells have been observed as well as functional differences in immune cell populations. Indeed, even the prenatal development of the embryonic piglet proceeds in a principally different way. However, it remains unclear to what extent these differences might contribute to the predisposition to and outcomes of bacterial infections, in particular those with zoonotic potential. In the following article we will review some of the peculiarities of the porcine immune system and consider possible implications for the course of infections in swine, with an emphasis on Salmonella serovars. 相似文献
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Florian Frers Maren Hellige Sandra Franke Christina Puff Uta Delling Karsten Feige 《Equine Veterinary Education》2023,35(2):e98-e104
A 7-year-old plains zebra (Equus quagga) mare was presented to the Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Germany as an emergency. The owner reported that the mare was unable to stand after a suspected traumatic episode at the home yard. The mare was transported in lateral recumbency in a trailer. Clinical examination revealed tachycardia (up to 102 beats/min), tachypnoea (28 breaths/min), mild fever (38.7°C) and clinical dehydration with elastic skin and dry and red mucous membranes. Neurological examination showed paraplegia with complete loss of nociception of the mid-thoracic region and caudal to it. In contrast, examination of the thoracic limbs revealed marked extensor rigidity and hyperaesthesia resulting in an enhanced acute response to minimal touch of the neck and shoulder region. Lateral radiographs of the thoracic vertebral column led to the diagnosis of a complete fracture of the vertebral body of the 7th thoracic (T) vertebra with suspected traumatic compression of the spinal cord. Post-mortem examination confirmed the diagnosis. Gross pathology revealed a complete comminuted fracture of T7 with marked compression of the spinal cord. This is the first report describing the clinical, radiological and pathological findings of a fracture of a thoracic vertebra leading to a Schiff-Sherrington syndrome in a zebra (Equus quagga). 相似文献
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Lasmar Chaim J. Queiroz Antônio C. M. Rosa Clarissa Carvalho Nathália S. Schmidt Fernando A. Solar Ricardo R. C. Paolucci Lucas N. Cuissi Rafael G. Ribas Carla R. 《Landscape Ecology》2021,36(9):2583-2597
Landscape Ecology - Harmful effects of habitat loss and fragmentation can be detected across multiple spatial scales, yet most studies that aim to characterize these effects take place at a single... 相似文献
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Walter Oettmeier Ursula Hilp Wilfried Draber Carl Fedtke Robert R. Schmidt 《Pest management science》1991,33(4):399-409
Weeds resistant to the s-triazine herbicide atrazine also show resistance to the triazinone herbicide metribuzin. However, with highly lipophilic triazinones, thylakoids isolated from atrazine-resistant Amaranthus retroflexus (mutation at position Ser264 of the photosystem II D-1 reaction centre protein) in general show a higher pI50 value in photosystem II electron transport than those from the wild type (i.e. negative cross-resistance; ‘supersensitivity’). A quantitative structure–activity relationship (QSAR) can be established, wherein the lipophilicity of the compound plays a major role. In in-vivo experiments, it was found that the triazinone DRW2698 killed resistant Amaranthus retroflexus and Chenopodium album whereas the wild type was almost unaffected. Triazinones were further investigated in five different mutants of Chlamydomonas rheinhardtii (mutations in the D-1 protein at positions Ser264, Ala251, Leu275, Phe255, and Val219). Inhibitory activity of all triazinones was generally enhanced in the Phe255 mutant but decreased in the Val219 mutant. In the other mutants, biological activity was decreased when position 3 of the triazinone was substituted by CH3, OCH3, SCH3, NHCH3 or N(CH3)2. However, negative cross-resistance was again observed when this position was occupied by free thiol. It is therefore suggested that these two groups of triazinones orient themselves differently within the herbicide binding niche of the photosystem II D-1 protein. 相似文献
20.
The metabolism of [ 14 C]-4-nitrophenol and [ 14 C]-3,4-dichloroaniline (the xenobiotics are degradation products of parathion and propanil, respectively) was studied in cell suspension cultures of carrot (Daucus carota L.). 4-Nitrophenol was transformed almost quantitatively to water-soluble conjugates with minor amounts of non-extractable residues. The conjugates identified were 1-(O-β-D-glucopyranosyl)-4-nitrobenzene and 1-(6′-O-malonyl-O-β-D-glucopyranosyl)-4-nitrobenzene. In addition, two unidentified metabolites were observed, possibly a disaccharide and another malonylated glycoside of 4-nitrophenol. Time-course studies demonstrated that 4-nitrophenol was rapidly taken up and conjugated; all metabolites remained associated with the cells rather than nutrient medium. 3,4-Dichloroaniline was transformed quantitatively to water-soluble conjugates and bound residues (3.6%). The water-soluble metabolites were identified as 6′-O-malonyl-N-(β-D-glucopyranosyl)-3,4-dichloroaniline, N-(β-D-glucopyranosyl)-3,4-dichloroaniline and N-malonyl-3,4-dichloroaniline. A time-course study showed that the glucosides were formed initially, then decreased, possibly due to hydrolysis. This decrease was paralleled by an increase of the main metabolite, N-malonyl-3,4-dichloroaniline, which was predominantly recovered from the medium. 相似文献