Sera from dams of calves with bovine neonatal pancytopenia contain alloimmune antibodies directed against calf leukocytes     

Pardon B  Stuyven E  Stuyvaert S  Hostens M  Dewulf J  Goddeeris BM  Cox E  Deprez P 《Veterinary immunology and immunopathology》2011,141(3-4):293-300

Bovine neonatal pancytopenia (BNP) is a bleeding and pancytopenic syndrome in neonatal calves, which recently emerged all over Europe. The present study tested whether antibodies directed against calf leukocytes are present in sera from known BNP dams. Sera from BNP dams (n=11) were combined with leukocytes from 11 calves (5 BNP survivors and 6 controls). After adding a fluorescein conjugated F(ab')(2) fragment of rabbit anti-bovine IgG (H&L) the level of antibody binding was measured by flow cytometry. As control groups both sera from dams from BNP affected (n=48) as from unaffected (n=54) herds were combined with leukocytes from the same calves. With sera from BNP dams, antibody binding could be visualised by immunofluoresence in both peripheral blood as in bone marrow smears. Mean fluoresence intensity values of all leukocyte subpopulations were significantly higher for the BNP dams compared to both control groups (P<0.01). BNP dams showed significantly more antibody binding on multiple leukocyte subpopulations of both BNP survivors and control calves and this from cut off values of MFI 100 onwards (P<0.01). The BNP survivor calves reacted significantly more often with sera from the BNP dams than the control calves (P<0.01). In conclusion the present study supports the hypothesis that BNP is an immune-mediated disease.  相似文献   

Impacts of Fire and Invasive Species on Desert Soil Ecology     

Edith B. Allen  Robert J. Steers  Sara Jo Dickens 《Strength and Conditioning Journal》2011,64(5):450-462

A review of literature shows that both fire and invasive species may cause changes in biological, chemical, and physical properties of desert soils. Although soil may recover from the impacts of fire during succession, these changes are permanent under persistent invasive species. The most severe effects of fire occur under high temperatures with high fuel buildup and soil moisture that conducts heat downward. Deserts typically have low fuel mass and low soil moisture, both conditions that would contribute to lower impacts of fire than in mesic soils. Soil is a good insulator, so soil microorganisms will survive a few centimeters deep even in hot surface fires. Immediately postfire there is often an increase in mineral nitrogen (N) and a decrease in soil carbon (C) and organic N, but these changes are often minimal in desert soils, except under fertile shrub islands that have higher fuel loads and fire temperature. Both hot and cold deserts have experienced slow recovery of native shrubs and increased growth of invasive grasses following fire. Invasive species may either increase or decrease soil N and C depending on fire temperature and site and species characteristics. Mineralization and fixation of N are often high enough after fire that subsequent productivity balances N losses. The elimination of islands of fertility coupled with postfire erosion may be a major impact after fire in grass-invaded shrub lands. In the long term, the interaction of fire and invasive species may result in more frequent fires that eliminate fertile islands and reduce the productivity of deserts. Managers may use fire as a tool to control desert invasives without the concern that N will be irrevocably lost, but this must be done judiciously to avoid eliminating shrubs and further increasing invasive species.  相似文献   

Local nanomechanical motion of the cell wall of Saccharomyces cerevisiae     

Pelling AE  Sehati S  Gralla EB  Valentine JS  Gimzewski JK 《Science (New York, N.Y.)》2004,305(5687):1147-1150

We demonstrate that the cell wall of living Saccharomyces cerevisiae (baker's yeast) exhibits local temperature-dependent nanomechanical motion at characteristic frequencies. The periodic motions in the range of 0.8 to 1.6 kHz with amplitudes of approximately 3 nm were measured using the cantilever of an atomic force microscope (AFM). Exposure of the cells to a metabolic inhibitor causes the periodic motion to cease. From the strong frequency dependence on temperature, we derive an activation energy of 58 kJ/mol, which is consistent with the cell's metabolism involving molecular motors such as kinesin, dynein, and myosin. The magnitude of the forces observed ( approximately 10 nN) suggests concerted nanomechanical activity is operative in the cell.  相似文献   

Relative Braunfäuleresistenz beiSolanum tuberosum ssp.andigena     

U. Darsow  Edith Hinze  H. Oertel  K. Schüler 《Potato Research》1993,36(2):161-170

Zusammenfassung Ergebnisse systematischer Prüfung auf relative Resistenz der Knollen von 1274 Herkünften der ssp.andigena (adg) genenüberPhytophthora infestans werden mitgeteilt. Die Methode des Kn?llchenstestes erm?glichte dabei das Eindringen des Pilzes direkt ins Knollenmark oder über die intakte Schale. Nur etwa 1% der Herkünfte enthielt einen Anteil von >25% Idiotypen mit gutem Resistenzniveau. Eine Analyse der Fundorte ergab keine Anhaltspunkte für die gezielte Suche von Resistenzquellen. Ergebnisse aus der züchterischen Nutzung von adg betreffen die ph?notypische Resistenz der Nachkommen und weitere Merkmale.

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Summary Results are reported of late blight resistance inS. tuberosum ssp.andigena (adg) and its use in breeding. Tests were carried out on material of the gene bank in Gross Lüsewitz (GLKS). Seedlings were cultivated under glass cover in a 6-years test period. To examine tuber resistance toPhytophthora infestans the following test was set up: 2–5 tubers per idiotype, up to 8 idiotypes per accession and year of test were taken and 1274 different accessions were examined with an average number of 23 idiotypes and 59 tubers from each. Inoculation was made by fresh deep cuts to the pith and by subsequent immersion in a solution of zoospores, 6–9×10⁴ ml⁻¹ with a mixture of the pathotypes (1.2.3.4.5.7.10.11, 1.2.3.4.7.8.10 and 1.2.3.4) at a temperature of 16–18°C and at an air humidity of >90%. Evaluation of the presence of aerial mycelium and browning after 7 days allowed the calculation of a resistance score (B_K): grade 9 (highly resistant) to grade 1 (highly susceptible). The mean values derived from the accessions (Fig. 1) revealed that a medium level of susceptibility is dominating and that they rarely exceed average levels of cultivars. Approximately 1% of the accessions contained ≥25% of idiotypes with B_K ≥6 and these may be interesting for breeding purposes. Table 1 shows the analysis of accessions with the most favourable mean values. Geographic evaluation did not yield indications for a more purposeful search for sources of resistance, since detailed reports on find-spots were missing (Table 2). Combination tests withPhytophthora-resistant genes of adg for crosses of adg withS. demissum (dms) andS. stoloniferum (sto) proved to be more useful as they partly showed good heritable resistance to haulm and tuber infection ofP. infestans (Table 3). The problem of the possible role of unknown r-genes is discussed. Only a few crosses with ssp.tuberosum (tbr) generated a progeny with sufficient resistance. Selection from such progeny over several years resulted after the second year in rejections, mainly because of susceptibility for viruses, too small tubers and lack of flowering (Table 4). Results of varietal research of the former German Democratic Republic proved that with the use of suitable parents in breeding for nematode resistance,Phytophthora susceptibility from adg could be balanced off (Table 5). The cultivar Auralia is a good example of the importance of adg in achieving a high level of resistance to late blight.

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Vaccine production in plant systems--an aid to the control of viral diseases in domestic animals: a review     

Loza-Rubio E  Rojas-Anaya E 《Acta veterinaria Hungarica》2010,58(4):511-522

Plants have been identified as promising expression systems for the commercial production of vaccines because of the possibility of introducing exogenous genes into them, which permits the development of a new generation of biological products called edible vaccines. The advantages of oral vaccines of this new type are that they induce mucosal, humoral, cellular and protective immunity, they are cheaper, easier to store, distribute and administer, they do not require cold chain management, and some species can be stored for long periods of time without any spoilage and may be administered as purified proteins. Owing to these benefits, plant-produced vaccines represent a valuable option for animal health. The aim of this paper is to present a review of plant-produced vaccines against viruses affecting domestic animals. Some aspects of the feasibility of their use and the immune response elicited by such vaccines are also discussed, as the balance between tolerance and immunogenicity is a major concern for the use of plant-based vaccines.  相似文献   

National surveillance for human and pet contact with oral rabies vaccine baits, 2001-2009     

Roess AA  Rea N  Lederman E  Dato V  Chipman R  Slate D  Reynolds MG  Damon IK  Rupprecht CE 《Journal of the American Veterinary Medical Association》2012,240(2):163-168

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Abdominal obesity and the prevalence of diabetes and intermediate hyperglycaemia in Chinese adults     

He Y  Zhai F  Ma G  Feskens EJ  Zhang J  Fu P  Van't Veer P  Yang X 《Public health nutrition》2009,12(8):1078-1084

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The Population Structure of Phytophthora infestans from the Toluca Valley of Central Mexico Suggests Genetic Differentiation Between Populations from Cultivated Potato and Wild Solanum spp     

Flier WG  Grünwald NJ  Kroon LP  Sturbaum AK  van den Bosch TB  Garay-Serrano E  Lozoya-Saldaña H  Fry WE  Turkensteen LJ 《Phytopathology》2003,93(4):382-390

ABSTRACT The population structure of Phytophthora infestans in the Toluca Valley of central Mexico was assessed using 170 isolates collected from cultivated potatoes and the native wild Solanum spp., S. demissum and S. xendinense. All isolates were analyzed for mitochondrial DNA (mtDNA) haplotype and amplified fragment length polymorphism (AFLP) multi-locus fingerprint genotype. Isolate samples were monomorphic for mtDNA haplotype because all isolates tested were of the Ia haplotype. A total of 158 multilocus AFLP genotypes were identified among the 170 P. infestans isolates included in this study. P. infestans populations sampled in the Toluca Valley in 1997 were highly variable and almost every single isolate represented a unique genotype based on the analysis of 165 AFLP marker loci. Populations of P. infestans collected from the commercial potato-growing region in the valley, the subsistence potato production area along the slopes of the Nevado de Toluca, and the native Solanum spp. on the forested slopes of the volcano showed a high degree of genetic diversity. The number of polymorphic loci varied from 20.0 to 62.4% for isolates collected from the field station and wild Solanum spp. On average, 81.8% (135) of the AFLP loci were polymorphic. Hetero-zygosity varied between 7.7 and 19.4%. Significant differentiation was found at the population level between strains originating from cultivated potatoes and wild Solanum spp. (P = 0.001 to 0.022). Private alleles were observed in individual isolates collected from all three populations, with numbers of unique dominant alleles varying from 9 to 16 for isolates collected from commercial potato crops and native Solanum spp., respectively. Four AFLP markers were exclusively found present in isolates collected from S. demissum. Indirect estimation of gene flow between populations indicated restricted gene flow between both P. infestans populations from cultivated potatoes and wild Solanum hosts. There was no evidence found for the presence of substructuring at the subpopulation (field) level. We hypothesize that population differentiation and genetic isolation of P. infestans in the Toluca Valley is driven by host-specific factors (i.e., R-genes) widely distributed in wild Solanum spp. and random genetic drift.  相似文献   

Strukturelle Veränderungen in Abhängigkeit verschiedener Luftschadstoffe     

D. Grill  G. Zellnig  Edith Bermadinger-Stabentheiner  Maria Müller 《European Journal of Forest Research》1993,112(1):2-11

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Results of a survey of owners of miniature swine to characterize husbandry practices affecting risks of foreign animal disease     

Marshall ES  Carpenter TE  Thurmond MC 《Journal of the American Veterinary Medical Association》2007,230(5):702-707

OBJECTIVE: To characterize husbandry practices that could affect the risks of foreign animal disease in miniature swine. DESIGN: Survey study. STUDY POPULATION: 106 owners of miniature swine. PROCEDURES: An online survey of owners of miniature swine was conducted to obtain information about miniature pig and owner demographics; pig husbandry; movements of pigs; and pig contacts with humans, other miniature swine, and livestock. RESULTS: 12 states, 106 premises, and 317 miniature swine were represented in the survey. More than a third (35%) of miniature swine owners also owned other livestock species. Regular contact with livestock species at other premises was reported by 13% of owners. More than a third of owners visited shows or fairs (39%) and club or association events (37%) where miniature swine were present. More than 40% of owners fed food waste to miniature swine. Approximately half (48%) of the veterinarians providing health care for miniature swine were in mixed-animal practice. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study indicated that miniature swine kept as pets can be exposed, directly and indirectly, to feed and other livestock, potentially introducing, establishing, or spreading a foreign animal disease such as foot-and-mouth disease. In addition, the veterinary services and carcass disposal methods used by miniature swine owners may reduce the likelihood of sick or dead pigs undergoing ante- or postmortem examination by a veterinarian.  相似文献