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71.
OBJECTIVE: To determine signalment, history, clinical signs, blood and plasma taurine concentrations, electrocardiographic and echocardiographic findings, treatment, and outcome of dogs with low blood or plasma taurine concentrations and dilated cardiomyopathy (DCM). DESIGN: Retrospective study. ANIMALS: 12 client-owned dogs with low blood or plasma taurine concentrations and DCM. PROCEDURE: Medical records were reviewed, and clinical data were obtained. RESULTS: All 12 dogs were being fed a commercial dry diet containing lamb meal, rice, or both as primary ingredients. Cardiac function and plasma taurine concentration improved with treatment and taurine supplementation. Seven of the 12 dogs that were still alive at the time of the study were receiving no cardiac medications except taurine. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that consumption of certain commercial diets may be associated with low blood or plasma taurine concentrations and DCM in dogs. Taurine supplementation may result in prolonged survival times in these dogs, which is not typical for dogs with DCM. Samples should be submitted for measurement of blood and plasma taurine concentrations in dogs with DCM, and taurine supplementation is recommended while results of these analyses are pending.  相似文献   
72.
Prevalence was estimated for Salmonella enterica serotype eneritidis (SE) in layer house environments (n = 200 layer houses) and house mice (n = 129 layer houses) in 15 states throughout the United States. Environmental swabs were collected from manure, egg belts, elevators, and walkways. Live-catch rodent traps were placed for 4-7 days. Swabs and house mice were submitted to the laboratory for bacterial culture. Overall, 7.1% of layer houses and 3.7% of mice were culture positive for SE. The highest prevalence was in the Great Lakes region of the United States, and no SE was recovered from houses or mice in the southeast region. Presence of SE in layer houses was associated with age/molting, floor reared pullets, and number of rodents trapped. Cleaning and disinfecting houses between flocks was associated with a reduced risk. The prevalence of SE in mice from environmentally positive houses was nearly four times that of mice from environmentally negative houses.  相似文献   
73.
A decline in T-cell-mediated immunity and transient state of immunosuppression after immunization has been reported in dogs. Nevertheless, dogs are still routinely vaccinated with polyvalent live vaccines and severe disease does not generally occur. In order to investigate these effects on the canine immune system and to elucidate possible mechanisms we determined the following immune parameters in the blood of 33 clinically sound German shepherd dogs before and after standard vaccination with a polyvalent vaccine against distemper, parvovirus, viral hepatitis, leptospirosis, kennel cough and rabies: white and differential blood cell count, the serum concentrations and/or activities of IL-1, IL-2, IFN-gamma, TNF-alpha, neopterin and IgG, natural killer (NK) cell activity, bactericidal activity and complement hemolytic activity, lymphocyte proliferation test (LPT) and nitroblue tetrazolium test (NBT).Our major findings were that significant postvaccinal decreases in T-cell mitogenic response to PHA and in neutrophil function and neopterin serum concentration were accompanied by simultaneous increase in plasma IgG and hemolytic complement activity. This suggests a transient shift in the balance between cell-mediated and humoral (T(H)1/T(H)2) immunity rather than immunosuppression.These results do not imply that dogs should not receive live vaccines, as the response to vaccines just seems to create a state of altered homeostasis when immunization elicits protection by humoral and cell-mediated immunity. However, these recognized compromises of immune function should be considered and vaccines still be applied only in healthy animals and strictly according to the rules and regulations given by the manufacturer.  相似文献   
74.
OBJECTIVE: To evaluate the antimicrobial susceptibility patterns of Salmonella isolates from feedlot cattle. DESIGN: Cross-sectional study. SAMPLE POPULATION: 263 Salmonella isolates. PROCEDURES: Fecal samples were collected from the floor of 2 pens in each of 100 feedlots. Two hundred eighty Salmonella isolates were recovered after bacteriologic culture from 38 pens. Of these, 263 isolates were available for antimicrobial susceptibility testing to 16 antimicrobials, using microbroth dilution breakpoint plates. RESULTS: Less than 5% of isolates were resistant to any of the antimicrobials tested, with the exception of sulfamethoxazole (15; 5.7%) and tetracycline (61; 23.2%). Most isolates (197; 74.9%) were susceptible to all antimicrobials tested, whereas 18 (6.8%) were resistant to 2 or more antimicrobials. The percentage of isolates with resistance to any antimicrobial varied by serotype. The percentage of isolates resistant to various antimicrobials was not related to concurrent use of antimicrobials in the feed. CONCLUSIONS AND CLINICAL RELEVANCE: With the exception of tetracycline and sulfamethoxazole, resistance of Salmonella isolates to any of the antimicrobials was uncommon. Most isolates were susceptible to all antimicrobials tested. Antimicrobial resistance was not related to the presence of antimicrobials in the ration being fed at the time of sample collection.  相似文献   
75.
In this study, we determined the occurrence of the tsh gene among 305 Escherichia coli isolates from chickens by means of the polymerase chain reaction and agglutination of chicken erythrocytes; 200 of those isolates were obtained from chickens with colisepticemia, 52 isolates were from lesions of cellulitis, and 53 were from feces of normal chickens. The tsh gene was found in 79 (39.5%) isolates from colisepticemia, in 10 (19%) cellulitis-derived E. coli isolates, and in two (3.8%) fecal isolates. Among the tsh+ strains, 68 (86%) isolates from colisepticemia and nine (90%) from cellulitis agglutinated chicken erythrocytes in the presence of mannose, after growing the strains on colonization factor antigen agar plates at 26 C, which confirms a correlation between mannose-resistant hemagglutination and expression of hemagglutinin Tsh. These results show, for the first time, the presence of the gene tsh in cellulitis-derived E. coli isolates; the high frequency of this gene among avian pathogenic E. coli isolates in Brazil indicates that its putative role as a virulence factor should be studied more thoroughly.  相似文献   
76.
164 total hip prostheses of different manufacturers were implanted over an 8-year period. Clinical records were evaluated with a complication rate of 29.0% (42 of 145 joints) or 31.7% (39 of 123 dogs). The complications encountered in dogs that received the modular hip prosthesis (Biomécanique, Bretigny-sur-orge, France) amounted to 16.3% (15 of 92), dogs that received a fixed head prosthesis (5 different manufactures) had 39% complications (28 of 72). Although the complication rate was influenced by different surgeons (n = 5) with different system predelictions and a different learning curve it was obvious that luxations (n = 6 of 10) and stem fractures (n = 5) more often occurred with the fixed head prosthesis systems. These stem fractures might be due to implant material failure or due to improper cementation followed by fatigue material failure. Femur fracture or infection were encountered with both prosthesis systems.  相似文献   
77.
ABSTRACT Ustilago hordei, the causal agent of barley covered smut, produces mating pheromones that break down to smaller peptide compounds that act as potent inhibitors of mating and germination in several fungi. The pheromones are members of the farnesylated family of proteins. Synthetic peptide analogs of the pheromone derivatives, ranging in size from 4 mers to full length pheromones, were farnesylated, methyl esterified, or both and tested for mating or teliospore germination inhibition with U. hordei or Tilletia tritici, respectively. N-Acetyl-S-farnesylcysteine, which inhibits processing of Ras, and other sulfur-containing compounds such as homocysteine or methionine, were likewise modified and tested. The most potent inhibitors were methionine methyl ester and modified 4-mer peptides from both pheromones. Alanine scanning of the inhibitory 4 mers determined that the native amino acid sequence was specific for a high level of activity. The sulfur amino acids appear to be required for inhibition. Glasshouse studies using selected antagonists of mating and teliospore germination as seed treatments inhibited covered smut of barley and common bunt of wheat, although the level of control was inconsistent. The use of pheromone-related antagonists to mating or teliospore germination is a promising, novel strategy for control of smut and bunt diseases.  相似文献   
78.
Cognition is recognized as an essential component of the living strategies of organisms and the use of cognitive approaches based on an organismic-centered-view is discussed as a strategy to aid the advancement of landscape ecology to a more independent scientific discipline. The incorporation of the theory of information, the theory of meaning and the Umwelt, and the biosemiotic models into the landscape ecology framework is described as the necessary step to create a common paradigmatic background and operational tools to develop basis for a cognitive landscape ecology. Three cognitive landscapes (neutrality-based landscape, individual-based landscape and observer-based landscape) have been described as the result of distinctive mechanisms to extract information from a cognitive matrix based on a growing literature of (bio)semiotic exchange. The eco-field hypothesis is presented as a new possibility to describe landscape processes according to an organismic-centered-view. The eco-field is defined as a spatial configuration carrier of a specific meaning perceived when a specific living function is activated. A species-specific cognitive landscape is composed of all the spatial configurations involved for all the living functions for a particular organism. Eco-field hypothesis offers a detailed vision of (habitat) environmental requirements and creates a novel conceptual bridge between niche, habitat, Umwelt and the methodological approaches of spatial ecology. Finally the eco-field hypothesis promises a new testing ground for experimental investigations in landscape ecology and in related disciplines including environmental psychology, cognitive ethology, cultural ecology, landscape aesthetics, design and planning.  相似文献   
79.
The effect of dietary carbohydrate complexity on growth, feed utilization, and glycemia was studied in European sea bass juveniles. Four isonitrogenous (50% crude protein) and isolipidic (15% crude lipids) diets were formulated to contain 20% pregelatinized maize starch (PGS diet), dextrin (DEX diet), maltose (MAL diet), or glucose (GLU diet). No effect of dietary carbohydrate complexity on growth was noticed. Feed efficiency and protein efficiency ratio were lower in fish fed the GLU diet than in the other groups, whereas the opposite was observed for feed intake. Plasma glucose peaked 3–4 h after feeding in fish fed the MAL and GLU diets, whereas in fish fed the PGS and DEX diets the peak was reached 5–6 h after feeding. Peak plasma glucose concentration (13 mmol/L) was higher in fish fed the GLU diet than the other diets (9 mmol/L). Shorter hyperglycemia duration was observed in fish fed the MALT and GLU diets (6 h) than the PGS and DEX diets (10 h). Complex carbohydrates delayed plasma glucose concentration peak compared with simple sugars, whereas the opposite was observed for hyperglycemia duration. Overall, dietary maltose, dextrin, and starch were apparently better utilized as energy source than glucose by European sea bass juveniles.  相似文献   
80.
Fumonisin contamination of maize grain starts in the field. Forecasting Fusarium infection and fumonisin synthesis could allow operators in the field to control contamination during the growing season and to make the best agronomic decisions for high quality yields while respecting the limits imposed by the European Union.A research project to develop a decision support system for the control of field-phase fumonisin contamination began in Italy in 2003. This paper presents a preliminary version of the engine of the decision support tool: FUMAgrain, a dynamic risk assessment model developed with data from the north of Italy. The structure of FUMAgrain is based on the pathosystem formed by maize, F. verticillioides and Ostrinia nubilalis (European Corn Borer). The elements of the pathosystem are simulated by three sub-models: (i) maize development, (ii) F. verticillioides infection and fumonisin synthesis, (iii) European Corn Borer wounding activity on maize grain. Inputs to the model are (i) planting date, (ii) hourly meteorological data including temperature, relative humidity, wind speed and rain intensity, (iii) information on the phenological development of the hybrid planted (flowering and dry-down), and (iv) information about the chemical treatment against European Corn Borer. FUMAgrain gives an initial risk alert at the end of flowering based on the meteorological conditions during this phase. A second alert follows maturation when an assessment is made from (i) maize grain moisture, (ii) European Corn Borer damage to the ear, and (iii) fumonisin synthesis risk. Following calibration and validation with data FUMAgrain demonstrated its good capability to simulate fumonisin synthesis in maize grain in Italy (calibration: R2 = 0.70; validation: R2 = 0.71) and its usefulness for determining the optimal harvest date while respecting grain safety levels required by the international market and limiting moisture content, hence drying costs.  相似文献   
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