Bovine blood neutrophil acyloxyacyl hydrolase (AOAH) activity during endotoxin and coliform mastitis     

Mehrzad J  Dosogne H  De Spiegeleer B  Duchateau L  Burvenich C 《Veterinary research》2007,38(5):655-668

The dynamics of blood neutrophil acyloxyacyl hydrolase (AOAH) activity, the appearance of endotoxin (lipopolysaccharide, LPS) in blood and the role of blood neutrophil AOAH in the severity of Escherichia coli and endotoxin mastitis were investigated in early postpartum dairy cows experimentally challenged with either endotoxin (n = 6) or E. coli (n = 6). The AOAH activity of blood neutrophils started to decrease significantly at post challenge hours (PCH) 6-24 and 12-24 in the endotoxin and E. coli-challenged groups, respectively; it returned to pre-challenged values at PCH 48 in both endotoxin- and E. coli-challenged groups. The cows were classified as moderate and severe responders according to milk production loss in the non-challenged quarters at PCH 48. There were no severe responders in the endotoxin-challenged group. In the E. coli-challenged group, only 1 severe responder was identified. The pre-challenge neutrophil AOAH activity of the severe responder was approximately 30% lower than that of moderate responders. No LPS was detected in the plasma of endotoxin-challenged cows; neither was it found in the plasma of moderate responders in the E. coli-challenged group at any PCH. However, at PCH 6, a remarkable amount of LPS was detected in the plasma of the severe responder from the E. coli-challenged group. Furthermore, neutrophil AOAH activity was increased by approximately 70% in the severe responder at PCH 6, but it increased by only approximately 15% in moderate responders. This was followed by a decreased neutrophil AOAH activity at PCH 12-24 and 24-72 in moderate and severe responders, respectively; the decreased AOAH activity at those PCH was more pronounced in the severe responder. The pronounced decreased neutrophil AOAH activity during mastitis often coincided with extreme leukopenia, neutropenia and a maximal number of immature neutrophils in the blood. Our results demonstrate that a decrease in neutrophil AOAH activity results in the appearance of LPS in the blood, and low blood neutrophil deacylation activity could be considered as a risk factor for severe clinical coliform mastitis.  相似文献   

Adherence of Actinobacillus pleuropneumoniae to primary cultures of porcine lung epithelial cells   总被引：2，自引：0，他引：2  

Boekema BK  Stockhofe-Zurwieden N  Smith HE  Kamp EM  van Putten JP  Verheijden JH 《Veterinary microbiology》2003,93(2):133-144

To study adherence of Actinobacillus pleuropneumoniae to porcine lower respiratory epithelium, a cell culture model was developed using primary cultures of porcine lung epithelial cells (LEC). Adherence assays were performed and results were compared with data obtained with swine kidney cells (SK6). A. pleuropneumoniae efficiently adhered to LEC with up to 62 bacteria per cell after 2h of incubation. Reference strain of serotype 3 (R3) adhered better to LEC than reference strains of serotypes 1 (R1), 7 (R7) and 8 (R8). Overall the adherence to LEC was more rapid and up to 30-fold more efficient than adherence to SK6 cells. In search for the mechanism involved in the adherence event, we tested the effect of LPS which has previously been demonstrated to cause adherence of the pathogen to upper respiratory epithelium. Adherence assays with LPS transposon mutants demonstrated unaltered (mutant with modification in core/lipid A moiety) or even three-fold more adherence (mutants lacking O antigen) compared to the parent micro-organisms. Purified LPS of strains R1, R3, R7 and R8 did not inhibit adherence of R8 to LEC either, suggesting that LPS and particularly the O-antigen are not essential for adherence of A. pleuropneumoniae to LEC. The efficient, LPS-independent adherence of A. pleuropneumoniae to LEC cells indicates that A. pleuropneumoniae may carry different, cell type-specific adhesins and that primary cultures of lower respiratory epithelium are valuable infection models in studying A. pleuropneumoniae pathogenesis.  相似文献   

F4 receptor-independent priming of the systemic immune system of pigs by low oral doses of F4 fimbriae     

Van den Broeck W  Bouchaut H  Cox E  Goddeeris BM 《Veterinary immunology and immunopathology》2002,85(3-4):171-178

Oral administration of F4 fimbriae of Escherichia coli induces intestinal mucosal immune responses in F4 receptor-positive (F4R(+)) pigs, but not in F4R(-) pigs. We examined whether F4 fimbriae in F4R(-) animals behave like a food antigen and can induce oral tolerance. Therefore, F4R(+) and F4R(-) pigs were fed 2mg of F4 and challenged i.m. to evaluate the effect of oral F4 on the systemic immune system. As control antigen, two different oral doses (2 and 600 mg) of OVA were used. Thirty days after the i.m. OVA challenge, the OVA-specific serum IgG titre in 600 mg-fed pigs was lower than that in non-fed animals, indicating that tolerance was induced. Conversely, in the 2mg-fed pigs a rapid increase of OVA-specific IgG with higher titres than those in non-fed pigs was seen following challenge, indicating a priming of the systemic immune system. A similar priming was seen in both F4-fed F4R(-) and F4R(+) pigs. Upon challenge, non-fed pigs displayed a primary immune response with a slow increase of F4-specific serum IgG, whereas F4-fed F4R(-) and F4R(+) pigs showed secondary responses with a rapid increase of serum IgG. This was expected in F4R(+) pigs, as in these animals oral F4 induces F4-specific antibody-secreting cells in the spleen, suggesting a priming of the systemic immune system. However, also the F4-fed F4R(-) pigs displayed a secondary response, despite the failure to detect a response upon oral F4 administration. These findings suggest that the F4 antigen, at a dose of 2 mg, behaves like a common food antigen in F4R(-) pigs, namely it induces a systemic priming.  相似文献   

Atypical canine recurrent alopecia     

Sophie I. J. Vandenabeele  Jan Declercq  Sylvie Daminet  Ilona Schwarzkopf  Hilde E. V. De Cock 《Veterinary dermatology》2014,25(1):56-58

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Sedative and antinociceptive effects of dexmedetomidine and buprenorphine after oral transmucosal or intramuscular administration in cats     

Nathalie Porters  Tim Bosmans  Mariëlla Debille  Hilde de Rooster  Luc Duchateau  Ingeborgh Polis 《Veterinary anaesthesia and analgesia》2014,41(1):90-96

ObjectiveTo compare sedation and antinociception after oral transmucosal (OTM) and intramuscular (IM) administration of a dexmedetomidine-buprenorphine combination in healthy adult cats.Study designRandomized, ‘blinded’ crossover study, with 1 month washout between treatments.AnimalsSix healthy neutered female cats, weighing 5.3–7.5 kg.MethodsA combination of dexmedetomidine (40 μg kg^?1) and buprenorphine (20 μg kg^?1) was administered by either the OTM (buccal cavity) or IM (quadriceps muscle) route. Sedation was measured using a numerical rating scale, at baseline and at various time points until 6 hours after treatment. At the same time points, analgesia was scored using a dynamic and interactive visual analogue scale, based on the response to an ear pinch, and by the cat’s response to a mechanical stimulus exerted by a pressure rate onset device. Physiological and adverse effects were recorded, and oral pH measured. Signed rank tests were performed, with significance set at p < 0.05. Data are presented as median and range.ResultsThere were no differences in sedation or antinociception scores between OTM and IM dosing at any of the time points. Nociceptive thresholds increased after both treatments but without significant difference between groups. Buccal pH remained between 8 and 8.5. Salivation was noted after OTM administration (n = 2) and vomiting after both OTM (n = 4), and IM (n = 3) dosing.Conclusions and clinical relevanceIn healthy adult cats, OTM administration of dexmedetomidine and buprenorphine resulted in comparable levels of sedation and antinociception to IM dosing. The OTM administration may offer an alternative route to administer this sedative-analgesic combination in cats.  相似文献   

Cytokine mRNA expression in synovial fluid of affected and contralateral stifle joints and the left shoulder joint in dogs with unilateral disease of the stifle joint     

de Bruin T  de Rooster H  van Bree H  Duchateau L  Cox E 《American journal of veterinary research》2007,68(9):953-961

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RAPD analysis of interspecific relationships in presumably apomictic Cotoneaster species   总被引：3，自引：0，他引：3  

Igor V. Bartish  Bertil Hylmö  Hilde Nybom 《Euphytica》2001,120(2):273-280

A few of the approximately 300 Cotoneaster species described are diploid but the majority appear to be polyploid. The occurrence of apomixis inpolyploid Cotoneaster species has been reported but never proven with genetic markers. We have used 76 polymorphic RAPD markers to investigate the breeding system and phenetic grouping of some critical taxa, including a total of 19 plant accessions representing 13 mostly European species in the series Cotoneaster. Three to four individual plants, raised from seed from the same original plant, were analyzed for each of three accessions to investigate the possible occurrence of apomictic seed set. Absolutely congruent RAPD profiles were encountered among seedlings from one accession, whereas we found one or two marker differences among seedlings from the other two accessions. Genetic similarities among the different accessions were analyzed with a UPGMA-derived dendrogram. The most deviant taxon was the Chinese C. albokermesinus. A group withC. soczavianus and C. tomentosus was rather isolated from the remainder, as was also C. kullensis. Among the remaining taxa, two well supported clusters were found: (1) C. antoninae and C. uralensis, and (2) C. integerrimus and C. raboutensis, whereas the other five species (C. canescens, C. niger, C. scandinavicus, C. juranus, C. cambricus) formed a poorly supported cluster with no clear substructuring. A principal coordinate analysis yielded results that were in good correspondence with the dendrogram. Again C. albokermesinus appears to be totally isolated from the other species. In addition, two well-defined and rather isolated groups were found: (1) C. tomentosus and C. soczavianus, and (2) C. antoninae and C. uralensis, with the remainder comprising a loosely defined group. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

CD8alphaalpha-mediated survival and differentiation of CD8 memory T cell precursors   总被引：1，自引：0，他引：1  

Madakamutil LT  Christen U  Lena CJ  Wang-Zhu Y  Attinger A  Sundarrajan M  Ellmeier W  von Herrath MG  Jensen P  Littman DR  Cheroutre H 《Science (New York, N.Y.)》2004,304(5670):590-593

Memory T cells are long-lived antigen-experienced T cells that are generally accepted to be direct descendants of proliferating primary effector cells. However, the factors that permit selective survival of these T cells are not well established. We show that homodimeric alpha chains of the CD8 molecule (CD8alphaalpha) are transiently induced on a selected subset of CD8alphabeta+ T cells upon antigenic stimulation. These CD8alphaalpha molecules promote the survival and differentiation of activated lymphocytes into memory CD8 T cells. Thus, memory precursors can be identified among primary effector cells and are selected for survival and differentiation by CD8alphaalpha.  相似文献   

Frequent long-distance plant colonization in the changing Arctic     

Alsos IG  Eidesen PB  Ehrich D  Skrede I  Westergaard K  Jacobsen GH  Landvik JY  Taberlet P  Brochmann C 《Science (New York, N.Y.)》2007,316(5831):1606-1609

The ability of species to track their ecological niche after climate change is a major source of uncertainty in predicting their future distribution. By analyzing DNA fingerprinting (amplified fragment-length polymorphism) of nine plant species, we show that long-distance colonization of a remote arctic archipelago, Svalbard, has occurred repeatedly and from several source regions. Propagules are likely carried by wind and drifting sea ice. The genetic effect of restricted colonization was strongly correlated with the temperature requirements of the species, indicating that establishment limits distribution more than dispersal. Thus, it may be appropriate to assume unlimited dispersal when predicting long-term range shifts in the Arctic.  相似文献   

Lignin degradation by Agaricus bisporus accounts for a 30% increase in bioavailable holocellulose during cultivation on compost     

ten Have R  Wijngaard H  Ariës-Kronenburg NA  Straatsma G  Schaap PJ 《Journal of agricultural and food chemistry》2003,51(8):2242-2245

The common mushroom Agaricus bisporus is a non-white rot saphrophytic fungus that can degrade lignin to free and utilize holocellulose embedded in fermented straw as present in compost. A new method is described to estimate the actual amount of bioavailable holocellulose in 3.8 kg compost cultures spawned with A. bisporus Horst U1 prior to and during a cultivation with two cycles of mushroom harvesting. The method shows that the initial amount of bioavailable holocellulose per culture, accounting for 130 +/- 22 g, is lower than the total holocellulose consumption by A. bisporus accounting for 182 +/- 15 g. This difference is explained by a 30% increase in bioavailable holocellulose. The increase is caused by the degradation of 95 +/- 3 g of holocellulose-shielding lignin. The results are discussed within the scope of the A. bisporus mushroom yield and lignin degradation by white rot fungi during growth on lignocellulose-containing materials.  相似文献