Effects of acute asphyxia at birth on subsequent heat production capacity in newborn pigs     

Herpin P  Wosiak F  Le Dividich J  Bertin R 《Research in veterinary science》1999,66(1):45-49

The effect of acute asphyxia at birth on subsequent ability to produce heat was investigated in 30 newborn pigs. A model of experimentally induced asphyxia consisting of the prevention of breathing within the first four minutes of life was used. Blood was sampled from an umbilical artery catheter within the first 75 minutes of life for blood gas, pH, glucose, lactate and catecholamine analysis. After the treatment and 24 hours later, heat production capacity, shivering intensity and rectal temperature were measured 10 degrees C below thermoneutrality. Effects on blood gas parameters were severe but transient whereas alterations in carbohydrate metabolism were maintained during the first 75 minutes (P < 0.05). Acute asphyxia at birth induced only minor alterations of thermoregulatory abilities during the first day of life: rectal temperature was lower one hour after birth (P < 0.05) and the postnatal increase in heat production capacity was less pronounced than in controls. It is suggested that the lower viability usually reported for piglets suffering from asphyxia during delivery is most likely to result from reduced vigour and colostrum intake, as well as altered carbohydrate metabolism early after birth.  相似文献   

Polymorphism of 14α-demethylase Gene (CYP51) in the Cereal Eyespot Fungi Tapesia acuformis and Tapesia yallundae     

Catherine Albertini  Michel Gredt  Pierre Leroux 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(2):117-128

Cereal eyespot fungi Tapesia acuformis and Tapesia yallundae are closely related species which show different behaviours upon treatment with sterol 14-demethylase inhibitors (DMIs). T. acuformis is naturally resistant to DMIs belonging to the triazole family and susceptible to the imidazole ones, whilst T. yallundae is sensitive to both inhibitors. Cloning of the target enzyme gene, CYP51, from the two species revealed an important polymorphism between them. Further sequencing of CYP51 from sixteen T. acuformis and eleven T. yallundae strains with different phenotypes with regards to resistance to DMIs confirmed that at least eleven variations are species related. Among them, a conserved phenylalanine residue at position 180, found both in T. yallundae and in all known CYP51 proteins from filamentous fungi and yeast, was replaced in T. acuformis by a leucine. Therefore, a leucine at 180 could be possibly involved in natural resistance of T. acuformis to triazoles. Other mutations were observed in some resistant strains, sometimes simultaneously, but in contrast to what was reported for other filamentous fungi, where a mutation at the 136 position of the CYP51 gene product seemed to correlate with resistance to DMIs, we did not find a clear relationship between a given mutation and a particular phenotype. This result suggests that resistance to DMIs could have a polygenic nature in Tapesia. We took advantage of species-related variations to develop a PCR-based assay allowing rapid and easy discrimination between field strains of the two species.  相似文献   

Gene discovery in Eimeria tenella by immunoscreening cDNA expression libraries of sporozoites and schizonts with chicken intestinal antibodies   总被引：4，自引：0，他引：4  

Réfega S  Girard-Misguich F  Bourdieu C  Péry P  Labbé M 《Veterinary parasitology》2003,113(1):19-33

Specific antibodies were produced ex vivo from intestinal culture of Eimeria tenella infected chickens. The specificity of these intestinal antibodies was tested against different parasite stages. These antibodies were used to immunoscreen first generation schizont and sporozoite cDNA libraries permitting the identification of new E. tenella antigens. We obtained a total of 119 cDNA clones which were subjected to sequence analysis. The sequences coding for the proteins inducing local immune responses were compared with nucleotide or protein databases and with expressed sequence tags (ESTs) databases. We identified new Eimeria genes coding for heat shock proteins, a ribosomal protein, a pyruvate kinase and a pyridoxine kinase. Specific features of other sequences are discussed.  相似文献   

Detection of Cryptosporidium oocysts in goat kid faeces: comparison of a latex agglutination test with three other conventional techniques     

Chartier C  Mallereau-Pellet MP  Mancassola R  Nussbaum D 《Veterinary research》2002,33(2):169-177

Detection of Cryptosporidium oocysts from goat kid faeces: comparison of a latex agglutination test with three other conventional techniques. A quantitative latex agglutination test (QLAT) with monoclonal antibodies for the detection of Cryptosporidium oocysts in faeces was compared with 3 other conventional techniques: Heine staining on faecal smears (HS) giving semi-quantitative results (scores from 1 to 5), sucrose flotation on diluted faeces (SF) with results expressed in oocysts/g of faeces (opg), direct ELISA (DE) giving qualitative results. Goat kid unconcentrated faecal samples (234) from 8 farms were processed according to the 4 techniques. Data were analyzed with Win Episcope 1.0 and Testview 1.1 softwares. The oocyst outputs ranged from 100 000 (detection limit for SF) to 200 millions opg (mean: 15.2 millions opg). A very good agreement was recorded between QLAT and HS, SF, DE: Kappa values ranged between 0.82 and 0.90. When considering the samples exhibiting oocysts (or not) as positive (or negative) using both HS and SF (n = 219), the sensitivity and specificity of QLAT were respectively 95.1 and 96.0%. The lack of sensitivity was observed in faeces harboring a few oocysts (< or = 200 000 opg, scores < or = 2) whereas the lack of specificity was only observed in 3 samples originating from the same farm. A significant correlation was calculated between the percentage of agglutination in QLAT and the number of oocysts in SF or scores in HS (Spearman correlation ranging from 0.45 to 0.48, p < 0.001). QLAT is a rapid, simple and reliable tool for routine detection of Cryptosporidium oocysts in faeces.  相似文献   

Early hepatic immune response in rats infected with Fasciola hepatica     

Tliba O  Moire N  Le Vern Y  Boulard C  Chauvin A  Sibille P 《Veterinary research》2002,33(3):261-270

We investigated the phenotype of the T cells (CD4+ and CD8+) that produced Th1 (IFN-gamma) and Th2 cytokines (IL-4 and IL-10) during the firsttwo weeks of experimental fasciolosis in rats. We also followed the kinetics of the cytokine and proliferative responses of hepatic mononuclear cells (HMNC) over the same period. We found that HMNC were more numerous in the infected animals than in the controls. The percentage of CD4+ cells increased significantly after infection, whereas the percentage of CD8+ cells did not change. Moreover, the frequency of the cells producing (CP) cytokine changed after infection. The frequency of CP IFN-gamma on 7 days postinfection (pi) was similar to that in control animals. However, the frequency of CP IFN-gamma was clearly lower on day 14 pi, whereas the frequency of CP IL-4 and CP IL-10 had increased. The CP IL-10-were mostly CD4+. Mitogenic stimulation (phorbol myristate acetate/ionomycin) of HMNC led to an increase in the amounts of the Th2 cytokines in the supernatant on days 7 and 14 pi, with the increase more pronounced on day 14. In contrast, IFN-gamma levels also increased by day 7 pi but then decreased to below control levels by day 14. In addition, HMNC proliferation in response to mitogen followed a similar pattern to IFN-gamma production. These findings suggested that, during the first 2 weeks of infection, F hepatica induced a transient ThO cytokine profile followed by downregulation of the cellular response and the induction of a Th2 cytokine profile.  相似文献   

Evaluation of the hepatic NK cell response during the early phase of Fasciola hepatica infection in rats     

Tliba O  Chauvin A  Le Vern Y  Boulard C  Sbille P 《Veterinary research》2002,33(3):327-332

The in situ distribution of NK cells in rat liver during the first 28 days of an experimental infection with F hepatica was investigated. NK cells were distributed homogeneously throughout the hepatic parenchyma in uninfected animals. The total number of hepatic mononuclear cells increased significantly following infection, but the proportion of NK cells did not change. After infection, these cells were found around the portal space, around the centrolobular vein, in the periportal fibrosis and in the band of collagen. However, no NK cells could be detected in or around the granuloma during infection. The frequency of both I L-2- and IFNgamma-producing NK cells was higher on day 7 postinfection (pi) but only the percentage of IFNgamma -CD161+ subsets remained elevated thereafter, whereas the percentage of both IL-2+CD161+ and IL-4+CD161+ subsets returned to the baseline. The number of CD161+IL10+ cells did not change significantly. These results suggest that NK cells could be another source for the early production of IFNgamma but provide no evidence that these cells are involved in early events associated with granuloma formation.  相似文献   

Sternal recumbency or suspension by the hind legs immediately after delivery improves respiratory and metabolic adaptation to extra uterine life in newborn calves delivered by caesarean section     

Uystepruyst C  Coghe J  Dorts T  Harmegnies N  Delsemme MH  Art T  Lekeux P 《Veterinary research》2002,33(6):709-724

The aim of this study was to evaluate the effect of body positioning immediately after delivery on respiratory and metabolic adaptation to extra-uterine life in newborn calves. One hundred and one Belgian White and Blue calves were delivered at term by an elective caesarean section and were assigned into three categories according to the body position imposed immediately after umbilical cord rupture: 71 calves were placed in lateral recumbency; 16 calves were placed in sternal recumbency and 14 calves were suspended by the hind legs for less than 90 seconds (75 +/- 5 s). Following this initial body position, the calves were allowed to move without restraint. They were examined at birth, 5, 15, 30, 45 and 60 minutes, and 2, 3, 6, 12 and 24 hours after birth by the following measurements: physical examination, heart rate, arterial blood gas analysis, pulmonary function tests using the esophageal balloon catheter technique, arterial and venous blood acid-base balance analysis, rectal temperature, jugular venous blood sampling for the determination of blood glucose, plasma lactate and serum cortisol concentrations, haematologic variables and passive immune transfer variables. Body positioning immediately after delivery clearly influenced respiratory and metabolic adaptation to extra-uterine life in term calves delivered by an elective caesarean section. Systematic sternal recumbency and suspension by the hind legs for less than 90 seconds immediately after umbilical cord rupture had a positive functional impact on postnatal pulmonary mechanics and gas exchange and on postnatal correction of mixed acidosis present at birth, contributing in turn to an enhanced passive immune transfer. These two body positions should be encouraged to improve adaptation at birth in healthy term calves delivered by an elective caesarean section. Evaluation of possible side-effects is required before application in severely asphyxiated calves.  相似文献   

Brucella intracellular life: from invasion to intracellular replication     

Gorvel JP  Moreno E 《Veterinary microbiology》2002,90(1-4):281-297

Brucella organisms are pathogens that ultimate goal is to propagate in their preferred niche, the cell. Upon cell contact the bacteria is internalized via receptor molecules by activating small GTPases of the Rho subfamily and by a moderate recruitment of actin filaments. Once inside cells, Brucella localizes in early phagosomes, where it avoids fusion with late endosomes and lysosomes. These early events require the control of Rab small GTPases, and cytokines such as the G-CSF. Then, the bacterium redirects its trafficking to autophagosomes and finally reaches the endoplasmic reticulum, where it extensively replicates. Some of the bacterial molecular determinants involved in the internalization and early events after ingestion are controlled by the BvrS/BvrR two component regulatory system, whereas the intracellular trafficking beyond this early compartments are controlled by the VirB type IV secretion system. Once inside the endoplasmic reticulum, Brucella extensively replicates without restricting basic cellular functions or inducing obvious damage to cells. The integrity of Brucella LPS on the bacterial surface is one of the required factors for Brucella intracellular survival, and therefore for virulence.  相似文献   

The use of herders’ accounts to map livestock activities across agropastoral landscapes in Semi-Arid Africa     

Turner  Matthew D.  Hiernaux  Pierre 《Landscape Ecology》2002,17(5):367-385

Improved understandings of the agricultural and range ecologies ofsemi-arid Africa require better information on the spatiotemporal distributionof domestic livestock across agropastoral landscapes. An empirical GIS-basedapproach was developed for estimating distributions of herded livestock acrossthree agropastoral territories (around 100 km² each)over a two-year period. Algorithms developed from regression analyses of herdtracking data (with R²s 0.67) are used to transform a morecomprehensive but incomplete set of data generated from herders accounts oftheir herds grazing itineraries (400 herds following 6500 itineraries). Theresulting characterization registers 40 000 days of livestock activitiesacross694 land units (averaging 70 ha) over the study period. This studydemonstrates that rural producers knowledge of their daily extractionpracticescan be translated to fine-grained characterizations of extraction densitiesacross mixed landscapes. The spatiotemporal distribution of livestock that isrevealed by this approach diverges strongly from that predicted bycommonly-usedpoint-diffusion estimation procedures. Instead, the distribution reflects localpatterns of land use, topography, vegetation, settlements, and water points.Grazing and nongrazing times spent in land units are not spatially correlatedand the seasonality of grazing pressure is spatially variable. Therefore, theecological impacts of livestock grazing are spatially variable at fine scalesand there is a significant potential for livestock-mediated nutrient transfersacross agropastoral landscapes. The georeferenced data produced by thisapproachnot only will help evaluate the impact and sustainability of differentmanagement practices but also provides a strong empirical base for improvedspatial modeling of herded livestock.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   

DNA sequences coding for the F18 fimbriae and AIDA adhesin are localised on the same plasmid in Escherichia coli isolates from piglets   总被引：3，自引：0，他引：3  

Mainil JG  Jacquemin E  Pohl P  Kaeckenbeeck A  Benz I 《Veterinary microbiology》2002,86(4):303-311

The adhesin-involved-in-diffuse-adherence (AIDA) afimbrial adhesin is produced by human, but not by animal, Escherichia coli, with the exception of German porcine verotoxigenic Escherichia coli (VTEC) [Clin. Diagn. Lab. Immunol. 8 (2001) 143]. Presence and localisation of DNA sequences (aidA) coding for and production of an AIDA adhesin were investigated in a collection of Belgian VTEC and non-VTEC E. coli isolated from piglets at weaning time. The 174 isolates were also studied by colony hybridisation for the presence of DNA sequences coding for the Stx2e verocytotoxin and the F18 fimbrial adhesin (fed): 71 were Stx2+F18+AIDA+, 26 were F18+AIDA+, 12 were AIDA+, two were Stx2+AIDA+, and one was Stx2+ only. Fifty-four of the 58 (F18+)AIDA+ isolates tested positive in a western blotting assay with an immune serum raised against the AIDA protein. Hybridisation with the AIDA gene probe on plasmid DNA profiles identified a probe-positive plasmid band in the 10 AIDA+ and in 24 of the 25 F18+AIDA+ isolates studied. Moreover in F18+AIDA+ isolates, only one plasmid band hybridised with both F18 and AIDA probes. These results confirm the presence of aidA-related genes in not only VTEC, but also non-VTEC, isolates from piglets and the production of an antigenically AIDA-related protein by the majority of probe-positive E. coli. Moreover the plasmid DNA hybridisation results suggest a localisation on the same plasmid of the aidA- and fed-related DNA sequences.  相似文献