ULTRASONOGRAPHIC FEATURES OF CANINE GASTROINTESTINAL STROMAL TUMORS COMPARED TO OTHER GASTROINTESTINAL SPINDLE CELL TUMORS

Canine gastrointestinal stromal tumors (GISTs) are a recent subtype of gastrointestinal spindle cell tumor recognized with the increasing use of immunohistochemistry. To our knowledge, no imaging features have been described in immunistochemically confirmed canine GISTs. The objective of this retrospective, cross‐sectional study was to describe ultrasonographic features of canine GISTs compared with other spindle cell tumors. Thirty‐seven dogs with an ultrasonographically visible gastrointestinal mass and a histopathologic diagnosis of spindle cell neoplasia were examined. Immunohistochemistry staining was performed for retrieved tissue samples to further differentiate the tumor type and each sample was interpreted by a single veterinary pathologist. Ultrasonographic features recorded examined included mass echogenicity, homogeneity, presence of cavitation, layer of origin, bowel wall symmetry, and loss of wall layering, location, size, vascularity, and evidence of perforation or ulceration. Tumor types included 19 GISTs, eight leiomyosarcomas, six leiomyomas, and four nonspecified sarcomas. Gastrointestinal stromal tumors were significantly more likely to be associated (P < 0.03) with abdominal effusion than other tumor types. There was overlap between the anatomical locations of all tumors types with the exception of the cecum where all eight tumors identified were GISTs. Besides location, there were no unique ultrasound features of GISTs that would allow distinction from other gastrointestinal spindle cell tumors. Similar to previous studies, GISTs appeared to be the most common spindle cell tumor associated with the cecum in our sample of dogs. The high frequency of abdominal effusion with GIST's was of unknown etiology could possibly have been due to septic peritonitis.     

Brainstem Auditory-Evoked Potentials in Holstein Cows

Brainstem auditory-evoked potentials (BAEP) were recorded from 29 Holstein cows in a typical clinical setting. The latencies of five positive peaks in the BAEP were measured, and latency-intensity functions were determined. The BAEP was similar to that reported in humans, dogs, horses, and other species. The responses were reproducible for each cow, with low variability between cows. Four peaks (I, II, III, V) were present in all recordings, and a fifth (IV) was present infrequently. All peak latencies decreased as click-stimulus intensity increased. The threshold for detection of the BAEP was higher than expected for the cow compared with the horse.     

The effect of pre-fast diet and transport on nitrogen metabolism of calves

Two trials were conducted to determine the effects of transport stress and pre-transport diet on N losses, blood chemistry and ruminal variables of steers. In each trial, 16 crossbred steers (261 kg avg weight) were assigned to four groups in a 2 X 2 factorial arrangement of treatments. Treatments consisted of either transported or non-transported groups and two pre-transport dietary regimens (alfalfa hay or a 50% concentrate diet fed for 3 d before fasting). The alfalfa hay contained 14.6% crude protein (CP) and had a calculated metabolizable energy (ME) content of 1.92 mcal/kg. The 50% concentrate diet contained 15.5% CP and had a calculated ME content of 2.23 mcal/kg. Steers in the transport group were transported for 13 h in trial 1 and 46 h in trial 2, while the remaining steers were not transported. Both groups were withheld from feed and water during the observation periods. Urine and feces were collected and blood samples were obtained at intervals during the observation periods. Transport increased (P less than .05) urinary and total N excretion and nonevaporative water losses compared with fasting alone. Calves fed the 50% concentrate diet had lower N and nonevaporative water losses than calves fed hay, probably due to lower pre-fast N and water intakes. Ruminal total volatile fatty acid (VFA) concentrations and molar proportions of propionate and butyrate declined (P less than .05) with time in all groups, while molar proportions of acetate and minor VFA increased. Results of these trials indicate transportation stress can cause a significant increase in total N excretion and nonevaporative water loss compared with feed and water deprivation alone. Losses of N and water were lower in calves fed a 50% concentrate diet rather than hay for 3 d before the fasting period, probably because of lower pre-fast N and water intakes.     

Lipopolysaccharides of the Heddleston serotypes of Pasteurella multocida

Lipopolysaccharides (LPS) were extracted from 13 of the 16 Heddleston serotypes of Pasteurella multocida by phenol-chloroform-petroleum ether (PCP). Serotypes 3, 9, and 13 were extracted only by phenol-water (PW). After extraction of LPS of serotype 9 by PW, an additional LPS was isolated by PCP. All LPS contained glucose, 2-keto-3-deoxyoctonate, and heptose. Two isomers of heptose, D-glycero-D-mannoheptose and L-glycero-D-mannoheptose, were found in serotypes 2 and 5. Antisera made against purified LPS of serotypes 2 and 5 reacted with both heat-stable antigens and LPS from serotypes 2 and 5 in the gel-diffusion precipitin test. Antisera against serotype 2 LPS protected turkeys against challenge with capsulated serotype 5, indicating that a structural relationship exists between LPS of strains that cause hemorrhagic septicemia and fowl cholera. Rhamnose was a component of serotype 9 LPS, and galactose was found in all LPS, except for serotype 11. The LPS of serotype 13 contained an isomer of heptose that has not been identified. The LPS had buoyant densities in CsCl of 1.40 +/- 0.0148 g/ml, and all hemagglutinated chicken and turkey, but not sheep or horse, RBC.     

Kinetic properties of the inhibition of juvenile hormone esterase by two trifluoromethylketones and O-ethyl,S-phenyl phosphoramidothioate

Some inhibition kinetic properties and in vivo inhibition of the plasma juvenile hormone esterase from the cabbage looper (Trichoplusia ni Hübner) by one phosphoramidothioate and two trifluoromethylketones were examined. O-ethyl,S-phenyl phosphoramidothioate was shown to react irreversibly with the enzyme in a time-dependent manner, and the inhibition reaction can be factored into a reversible step with a dissociation constant, K_d, of 4.55 × 10^?5M followed by a phosphorylation step with a rate constant, k₂, of 1.98 min^?1. The phosphorylated enzyme did not show spontaneous recovery after 48 hr of dialysis. On the other hand, the two trifluoromethylketones were shown to act as reversible inhibitors, as their inhibited enzyme was regenerated completely after dialysis. However, 1,1,1,-trifluoro-3-thiooctylpropan-2-one, in contrast to 1,1,1-trifluorotetradecan-2-one, showed progressive time-dependent inhibition, and its reaction with the enzyme followed characteristic bimolecular second-order kinetics with a rate constant, k_i, of 3.37 × 10⁷M^?1 min^?1. The in vivo inhibition data of topically treated larvae at equimolar amounts of the tested compounds indicated rapid penetration, and the stability of the inhibition was higher for the phosphoramidothioate than for the trifluoromethylketones. The relationship of the mechanism of inhibition and the in vivo inhibition of these compounds to the understanding of the interactions between juvenile hormone and juvenile hormone esterase is discussed.     

The Effects of Timing of an Interim Harvest on the Yield and Composition of Lablab purpureus

Lablab purpureus was grown in two field experiments in consecutive years to evaluate the effects of the timing of an interim harvest on the yield and nutritive value of the harvested material and the subsequent regrowth, which was determined from the second and final harvest. Delaying the first harvest to 50–70 days post-sowing increased the total (first plus second harvests) dry matter (DM) yield, with a greater first harvest and reduced second harvest DM yield. The delay also reduced the crude protein concentration of the first harvest and tended to increase its modified acid-detergent (MAD) fibre concentrations. The delay increased the crude protein concentration and decreased the MAD fibre concentration of the second harvest. The total crude protein yield of both harvests increased with late interim harvesting. The first harvest plant calcium concentration increased and phosphorus concentration decreased with a delay in the interim harvest. It is concluded that, in the difficult growing conditions of the Sahelian zone of sub-Saharan Africa, delaying the interim harvest of Lablab purpureus until 50–70 days post-sowing will have beneficial effects on total dry matter and crude protein yields.     

Potential environmental and economic impacts of turfgrass in Albuquerque,New Mexico (USA)

We estimated the ecological and economic impact of urban turfgrass production in a large city. A satellite image was used to evaluate the turfgrass area of Albuquerque, New Mexico, U.S.A. Turfgrass, the major vegetation component of the city, covers 7,650 ha and represents approximately 30.0% of the metropolitan area. Of the total grass area, 85.0% exists as home lawns, 8.3% occurs in parks, and 6.7% is on golf courses.We estimated that turfgrass uses an average of 475,000 m³ of water every day, yielding more than 4,575,000 kg of grass clippings going to the landfill in approximately 250,000 garbage bags each year. The approximate yearly cost of maintenance comes to more than $30 million which includes the potential purchase of 322,065 kg of nitrogen fertilizer, 286,110 kg of phosphorus fertilizer, 237,915 kg of potassium fertilizer and 37,408 kg of active ingredients of insecticides.Our evaluation of the cumulative effects of domestic and municipal turfgrass production can guide the application of economically sound Integrated Pest Management strategies and enable planning for sustained use of potentially limiting resources, such as water, in semiarid environments.     

Establishment of dose-response relationships in BALB/c mice, using Brucella cell surface protein and lipopolysaccharide

A study was conducted to determine the immune (increased antibody) and protective (reduced colony-forming units) responses induced in mice by a: (i) single vaccinal inoculation, using various concentrations of Brucella cell surface protein (BCSP) or lipopolysaccharide (LPS); (ii) primary inoculation, using various concentrations of BCSP, followed by a secondary inoculation, using a standard concentration of BCSP; and (iii) primary inoculation, using 1 concentration of BCSP or LPS, followed by a secondary inoculation, using various concentrations of BCSP or LPS. Four weeks after the primary inoculation, mice were challenge exposed with approximately 1 x 10(4) colony-forming units of Brucella abortus strain 2308 and all mice were euthanatized at 6 weeks. Reduced splenic weights and reduced colony-forming units in the spleens of vaccinated mice, compared with nonvaccinated mice, were the criteria of protection. Increase in serum IgM and IgG was defined as immunity. Both BCSP and LPS induced protective and immune responses that were proportional to the dose given up to an optimal limit. However, concentrations higher than optimal decreased the protective and immune responses. This was true for mice given either 1 or 2 vaccinal inoculations. Enhanced secondary protective responses were seen only when suboptimal doses were used in the primary inoculation. Excessive or optimal doses in the secondary inoculations prevented or obscured the protectiveness and immunity by primary inoculations. The protective effects appeared to be additive when suboptimal doses were used in the primary and secondary inoculations.(ABSTRACT TRUNCATED AT 250 WORDS)