CONTRAST-ENHANCED ULTRASONOGRAPHY IN NORMAL CANINE LIVER. EVALUATION OF IMAGING AND SAFETY PARAMETERS

Contrast-enhanced ultrasonography, a new imaging modality in veterinary medicine, can provide data on tissue perfusion. The objective of this study was to use the ultrasonographic contrast agent SonoVue to evaluate various transit time indices in the normal canine liver, to examine the effect of anesthesia on these parameters, and to evaluate the safety of this agent in dogs. The liver of 11 healthy dogs was studied by ultrasound during an intravenous bolus injection of SonoVue. Each dog underwent the examination twice, first with and later without the use of anesthesia. A time-intensity curve was generated from a selected region of interest within the liver from each scanning session. Ratios derived from peak enhancement, time to peak enhancement, up-slope and full-width half-maximum (FWHM) of the curve were calculated from the time-intensity curves, and are reported. There were no statistically significant differences (P > 0.05) in peak enhancement, up-slope and FWHM between dogs that were anesthetized and dogs that were not. Time to peak enhancement, however, was significantly shorter when the dogs were anesthetized than when they were nonanesthetized (P < 0.05). There were no biologically significant changes in clinical laboratory findings. This study indicates that contrast-enhanced ultrasound using SonoVue gives reproducible liver perfusion data, and appears to be a safe and well-tolerated agent for use in dogs. When considering normal values, the use of anesthetic drugs has to be considered.     

In vitro insecticidal effects of fipronil and beta-cyfluthrin on larvae of the blowfly Lucilia sericata

The insecticidal effects of the phenylpyrazole, fipronil, and a pyrethroid, beta-cyfluthrin, on larvae of the blowfly Lucilia sericata were determined in laboratory assays. When first stage larvae of L. sericata were reared on homogenized pig liver which had been treated with known amounts of test compounds, both fipronil and beta-cyfluthrin induced significant levels of mortality compared to acetone and water controls. However, fipronil was approximately 10 times more toxic than beta-cyfluthrin to L. sericata larvae following ingestion. Beta-cyfluthrin had little effect on mortality until concentrations of approximately 0.5 ppm were reached. In contrast, fipronil effected L. sericata mortality at a concentration of 0.05 ppm and 100% mortality was reached by 0.5 ppm. The lethal concentration (LC50) value for beta-cyfluthrin was 1.56 ppm as compared to 0.14 ppm for fipronil. Following contact of first and third stage larvae with cloth impregnated with known amounts of test compound, the mortality profiles of fipronil and beta-cyfluthrin were similar. At short contact times, the LC50 values for fipronil were lower than those for beta-cyfluthrin. However, at the highest contact time evaluated for the first stage larvae, 300 s, there was a reversal in this trend. The results suggest that the phenylpyrazole fipronil may represent a new potential insecticide for development against blowfly strike of sheep.     

Phenotypic characterisation of Phaeoacremonium and Phaeomoniella strains isolated from grapevines: enzyme production and virulence of extra-cellular filtrate on grapevine calluses

Extra-cellular enzyme production of different Phaeoacremonium spp. and Phaemoniella chlamydospora isolates were used to assay the possibility of inter-specific characterisation. Isolates of Phaeoacremonium aleophilum, Phaeoacremonium angustius, P. viticola and Ph. chlamydospora were grown on solid media and the activities of extra-cellular amylases, lipases, proteases, cellulases, xylanases, laccase, polygalacturonase, pectate lyase, lignin peroxidase, manganese peroxidase, urease and chitinase were assayed. Phaeoacremonium species showed activities of a larger number of enzymes and also enzyme activity was frequently higher suggesting that Phaeoacremonium can be more virulent. To assay if the produced extra-cellular enzymes could reflect the virulence capacity of the two genera, calluses of Vitis vinifera L. (cvs. Baga and Maria Gomes) and of a rootstock (R3309) were inoculated with filtrated culture liquid medium of three isolates of Ph. chlamydospora and one of P. angustius. Filtrates from all strains decreased callus growth and membrane integrity, while soluble protein content of calluses decreased with the strains CAP 054 and 1AS. P. angustius (CAP 054) induced the more severe symptoms in all genotypes. Water content decreased together with an increase of osmolality in both cultivars but not in rootstock suggesting that osmorregulatory capacity is more affected in cultivars. Data show that: (1) Phaeoacremonium and Phaeomoniella genera have different patterns of extra- cellular enzymatic production; (2) these fungi produce extra-cellular compound(s) that induce(s) senescence symptoms in plant cells inhibiting callus proliferation; (3) among the strains tested in plant calluses the most virulent isolate (CAP 054) also produced higher amounts of some extra-cellular enzymes; (5) rootstock calluses were less sensitive to inoculation than grapevine calluses.     

<Emphasis Type="Italic">Physalis ixocarpa</Emphasis> and <Emphasis Type="Italic">P. peruviana</Emphasis>, new natural hosts of <Emphasis Type="Italic">Tomato chlorosis virus</Emphasis>

Tomato chlorosis virus causes yellow leaf disorder epidemics in many countries worldwide. Plants of Physalis ixocarpa showing abnormal interveinal yellowing and plants of Physalis peruviana showing mild yellowing collected in the vicinity of tomato crops in Portugal were found naturally infected with ToCV. Physalis ixocarpa and P. peruviana were tested for susceptibility to ToCV by inoculation with Bemisia tabaci, Q biotype. Results confirmed that ToCV is readily transmissible to both species. The infection was expressed in P. ixocarpa by conspicuous interveinal yellow areas on leaves that developed into red or brown necrotic flecks, while P. peruviana test plants remained asymptomatic. Infected plants of both P. ixocarpa and P. peruviana served as ToCV sources for tomato infection via B. tabaci transmission. This is the first report of P. ixocarpa and P. peruviana as natural hosts of ToCV.     

A Simple Apparatus for Frequent Measurement of Gastrointestinal Intraluminal PCO2

The accuracy and precision of an end-tidal infrared CO₂ monitor and customized capnography tubing system designed to measure gastrointestinal intraluminal CO₂ partial pressure (P_iCO₂) were tested in vitro. Samples were taken from the customized capnography tubing placed in either 5% or 10% CO₂ gas at discrete intervals ranging from one minute to twelve minutes. For a given time interval, the tubing PCO₂ measurement was a constant fraction of the actual PCO₂ (all standard errors < 0.02). For increasing time intervals, the ratio of the tubing PCO₂ to actual PCO₂ increased logarithmically. In the 5% and 10% CO₂, the regression coefficients were 0.89 and 0.85 for 8 French tubing and 0.99 and 0.91 for 6 French tubing. Beacuase of its accuracy and precision, this system may provide automated gastrointestinal CO₂ partial pressure monitoring at short intervals (e.g. 5 minutes), facilitating testing of the role of gastrointestinal P_iCO₂ information in treatment algorithms. (Vet Emerg & Crit Care, 1998; 8: 109–116)     

Hemolytic potential of guaifenesin in cattle

The hemolytic effect on bovine red blood cells of 5%, 10%, and 15% guaifenesin solutions in 5% dextrose, 0.9% saline (NaCl), or distilled water was determined in vitro at 2 plasma concentrations (250 micrograms/ml, 500 micrograms/ml). A solution of 5% guaifenesin in a 5% dextrose solution or 5% guaifenesin in 0.9% saline produced minimal hemolysis in vitro. The amount of hemolysis of bovine red blood cells in vitro was related to the concentration of guaifenesin, diluent (5% dextrose, 0.9% NaCl, distilled water) and the plasma concentration of guaifenesin. In addition, plasma hemoglobin was determined in 4 adult dairy cows following the IV administration of 5% and 10% guaifenesin. These studies suggest that a solution of 5% guaifenesin in 5% dextrose is the most suitable solution for clinical use in cattle.     

Growth,Feed Utilization,and Glycemic Response in European Sea Bass,Dicentrarchus labrax,Juveniles Fed Carbohydrate of Different Complexities

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.     

Characterization of Canadian isolates of Chondrostereum purpureum by protein content,API ZYM and isozyme analyses

Seventeen isolates of Chondrostereum purpureum, collected from New Brunswick, Vancouver Island, and south-eastern British Columbia, Canada, were compared to determine the degree of genetic variation among isolates from different host species and different biogeographic locations. Several characteristics, including mycelial protein content, fungal biomass, API ZYM profile (semi-quantitative assay to detect the presence of 19 different enzymatic activities in an organism), and isozyme patterns were measured in these isolates. All 17 isolates shared similar API ZYM profiles, with only minor variation observed in the level of expression of specific enzymes. Of the 13 isozyme systems examined, eight (acid phosphatase, alkaline phosphatase, β-esterase, β-glucosidase, malate dehydrogenase, peroxidase, phosphoglucomutase, and polyphenoloxidase) produced measurable activity. No qualitative differences were observed between the isolates for all of these enzymes. There appeared to be limited variation between the isolates collected from across Canada and there was no correlation between specific API ZYM, and isozyme patterns and either host plant or geographical source of the isolates.