Inducible nitric oxide synthase and nitrotyrosine in listeric encephalitis: a cross-species study in ruminants     

Pfister H  Remer KA  Brcic M  Fatzer R  Christen S  Leib S  Jungi TW 《Veterinary pathology》2002,39(2):190-199

Listeria monocytogenes (LM) is a Gram-positive facultative intracellular bacterium that causes fatal meningoencephalitis in humans and ruminants. A current paradigm predicts that intracellular bacteria are controlled by nitric oxide (NO) whose synthesis is catalyzed by inducible nitric oxide synthase (iNOS). The ability of macrophages (Mphi) to express iNOS shows extreme interspecies variability. Here the expression of iNOS and synthesis of NO was studied in listeric encephalitis of cattle, sheep, and goats. iNOS was expressed by a subset of Mphi in cerebral microabscesses in all three species. The level of iNOS expression and the density of cells per lesion expressing iNOS was highest in cattle, intermediate in sheep, and lowest in goats. The accumulation of nitrotyrosine (NT), an indicator of local NO synthesis, was observed in lesions of cattle but not in those of small ruminants. The density of iNOS-expressing cells in lesions was inversely correlated with the number of bacteria. No species differences were observed in regard to reactive oxygen intermediate (ROI) production by stimulated granulocytes, using the flow cytometric dihydrorhodamine-123 (DHR) method indicating ROI generation. Thus, the marked species differences in iNOS expression, NT accumulation, and LM content in lesions of ruminants with listeric encephalitis are explained by different amounts of ROI produced. It suggests that variations in the ability of Mphi to synthesize NO are of pathophysiological significance in listeriosis.  相似文献   

Buchbesprechung/Book Review     

K. Pfister 《Anatomia, histologia, embryologia》2007,36(6):470-470

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The seasonal epidemiology of gastrointestinal nematodes in N'Dama cattle in The Gambia   总被引：2，自引：0，他引：2  

J Kaufmann  K Pfister 《Veterinary parasitology》1990,37(1):45-54

From June 1987 to June 1988, a total of 180 N'Dama cattle were necropsied to identify and enumerate parasites present, including 39 sick calves and 25 dead calves from local village herds, and 116 adult cattle from a local abattoir. Of 175 animals infected with one or more helminths (97%), Haemonchus contortus was found in 67% of all necropsied animals, Cooperia punctata in 75%, Cooperia pectinata in 55%, Oesophagostomum radiatum in 71% and Bunostomum phlebotomum in 21%. There was a wide range of worm burdens (0-22 925) and a pronounced seasonal pattern occurred. Eighty-two percent of the total adult Haemonchus burden occurred during the rainy season (June-October). By the end of the rainy season, almost 100% of the Haemonchus burden was present as inhibited larvae. By contrast, a different survival strategy appeared to occur in Cooperia spp.; Oesophagostomum spp. and Bunostomum spp., which were found as adults throughout the year. Results indicated that, apart from malnutrition during the dry season, gastrointestinal nematode infections, especially haemonchosis, represent a major constraint on the health and productivity of N'Dama cattle under West African savanna conditions.  相似文献   

Lupine induced "crooked calf disease" in Washington and Oregon: identification of the alkaloid profiles in Lupinus sulfureus, Lupinus leucophyllus, and Lupinus sericeus     

Lee ST  Cook D  Panter KE  Gardner DR  Ralphs MH  Motteram ES  Pfister JA  Gay CC 《Journal of agricultural and food chemistry》2007,55(26):10649-10655

Several lupines (Lupinus spp.) present on western U.S. rangelands contain alkaloids that are teratogenic to livestock and cause congenital birth defects in calves (crooked calf disease). Periodically, large losses of calves due to lupine-induced "crooked calf disease" occur in northern Oregon and eastern Washington state. Five lupine populations from this area representing three species (L. leucophyllus, L. sulfureus, and L. sericeus) were evaluated taxonomically and by gas chromatography/mass spectrometry, and the major alkaloids in each lupine species were identified. The teratogenic alkaloid anagyrine was present in both of the lupine species responsible for the high outbreaks in east-central Washington and northeastern Oregon. However, the alkaloid profiles of the two lupines identified as L. leucophyllus were dissimilar, as were the alkaloid profiles of the two lupines identified as L. sulfureus. Botanical classification is not sufficient to determine potential teratogenicity, and it must be followed by chemical characterization to determine risk to livestock.  相似文献   

Catch efficiency and retentive ability of commercial crawfish traps     

Vernon A. Pfister  Robert P. Romaire 《Aquacultural Engineering》1983,2(2):101-118

The catch efficiency and retentive ability of 10 commercial crawfish traps were evaluated in commercial ponds. Trap designs with three entrance funnels caught significantly more crawfish than did trap designs with one or two funnels. Conversely, the retentive ability of the trap designs was inversely related to the number of entrance funnels.Traps constructed from PVC plastic-coated wire caught significantly more crawfish than identical trap designs made from galvanized wire; however, retentive ability of traps was not related to construction material. The posture (horizontal versus vertical) of identically designed traps when set in the pond did not affect the catch efficiency nor retentive ability of the traps. Traps with exposed bait caught 40–47% more crawfish than did traps with protected bait. An average of 84, 80 and 64% of marked crawfish were retained by traps after 12, 24 and 48 h, respectively.  相似文献   

Biological nitrogen fixation in Lake Erie   总被引：4，自引：0，他引：4  

D L Howard  J I Frea  R M Pfister  P R Dugan 《Science (New York, N.Y.)》1970,169(940):61-62

Biological nitrogen fixation, as determined by acetylene reduction, occurs in Lake Erie. Fixation potential by blue-green algae in situ in water and by bacteria in collected sediments was demonstrated. Nitrogen-fixing activity occurred from June through November suggesting that it is significant over the extremes of seasonal variation in light, temperature, and nutrients.  相似文献   

Aldrin: removal from lake water by flocculent bacteria     

W O Leshniowsky  P R Dugan  R M Pfister  J I Frea  C I Randles 《Science (New York, N.Y.)》1970,169(949):993-995

Floc-forming bacteria isolated from Lake Erie adsorb and concentrate aldrin from colloidal dispersion so that the settling of the bacterial flocs removes aldrin from the water phase. Contemporary sediments forming in Lake Erie contain aldrin and could adsorb more. The sediments consist of a conglomerate floc of bacteria, diatoms, and inorganic and detrital particles. Flocculent bacteria also adsorb microparticulates, and this adsorption capacity represents a mechanism for sediment formation and for the removal of suspended particles including aldrin from the water column.  相似文献   

Control of bovine fasciolosis     

Knubben-Schweizer G  Scheuerle M  Pfister K 《Tier?rztliche Praxis. Ausgabe G, Grosstiere/Nutztiere》2011,39(3):179-85; quiz 186-7

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Bacterial community structure in lake sediments of microcosms contaminated with nonylphenol     

Miriam Jontofsohn  Gerd Pfister  Gabriele Severin  Karl-Werner Schramm  Anton Hartmann  Michael Schloter 《Journal of Soils and Sediments》2002,2(4):211-215

The impact of nonylphenol, an estrogenic degradation product of alkylphenol polyethoxylates, on the bacterial community structure in contaminated sediments of aquatic microcosms was investigated over a period of 20 weeks using a 16S rDNA-based molecular phylogenetic approach. All microcosms showeda strong seasonal fluctuation of the dominant as well as the active bacterial microflora independent of their degree of contamination with nonylphenol. These changes were correlated with the dynamic of the total organic carbon content (TOC), ranging from 4–39 g/kg sediment dry weight and the redox potential in the sediment. Even at the highest observed nonylphenol concentration (3.4 mg/kg sediment dry weight) the bacterial community structure was mostly unchanged.  相似文献   

The Importance of Precedent Hydro-climatological Conditions for the Mass Transfer of Pollutants in Separated Sewer Systems and Corresponding Tributaries During Storm Events     

Andreas Krein  Merce Salvia-Castellvi  Jean Francois Iffly  Laurent Pfister  Lucien Hoffmann 《Water, air, and soil pollution》2007,182(1-4):357-368

Runoff events were analysed in separated sewer systems in the town of Luxembourg. The relationships between Event Mean Concentrations of different pollutants and runoff patterns were evaluated. In addition, the inter-storm and intra-storm variability of the material transport were determined. Primarily, the variations in pollutant concentrations and loads are determined by the antecedent weather conditions. The presence of illicit sanitary inputs in one of the sewers produced a significant first flush effect as well as higher Event Mean Concentrations for pollutants. Furthermore, near the town of Trier 40 storms were analyzed in a small natural basin mainly influenced by runoff from a separated sewer system. Natural and artificial storm events were investigated in order to estimate the relationship between the pollutant sources in the channel and from the separated sewer system. Just like in the canalization of Luxembourg City the pollutant dynamics during natural storms are strongly influenced by pre-event hydrological conditions. The artificial storms behave differently. Despite little pre-rain, the maximum concentrations of toxic substances are comparatively low. A resuspension of sediment only occurs in the natural channel system, without the introduction of fines from the sewer system.  相似文献