The antibody response to pseudorabies virus nucleocapsid proteins (NCP) was evaluated by the western immunoblot analysis before and after challenge of immunity by nasal inoculation of 10(2.3) plaque-forming units of virus in 10 pigs that had been vaccinated with pseudorabies virus envelope glycoproteins. Antibody to 5 NCP with molecular mass of 140, 63, 41, 34, and 23 kD was first detected in vaccinated and nonvaccinated pigs on day 14 after challenge of immunity. Antibody to 2 of the 5 NCP continued to be detected through day 113 in 9 of 10 vaccinated pigs. Beyond day 32, antibody to NCP was not detected in 1 vaccinated pig. The 23-, 34-, and 41-kD proteins were the most immunogenic. Antibody to each of these proteins was first detected on day 14 in 10, 10, and 8 pigs, respectively. Seven, 6, and 8 pigs, respectively, were antibody-positive for these proteins on day 113. The 140- and 63-kD proteins were the least immunogenic. Antibody to these proteins was detected in 8 and 9 pigs, respectively, on day 14, and in 4 and 5 pigs, respectively, on day 113. Chi-square analysis for dependency indicated that the antibody response to the 140- and 63-kD proteins was interdependent. These results suggested that combinations of NCP may be useful as non-vaccine diagnostic antigens.

Skeletal muscles from healthy dogs and Labrador Retrievers with hereditary muscular dystrophy were examined morphologically and histochemically and were analyzed biochemically for Na+, K+, Ca2+, Mg2+, Zn2+, Cu2+, Cl-, total muscle water, and total neutral lipid content. Flame atomic absorption spectrophotometer was used for elemental quantitation of hydrochloric acid tissue extracts. Muscle samples from dystrophic dogs contained substantially increased concentrations of Na+, Ca2+, Zn2+, Cu2+, and Cl-, and a considerable reduction in the content of K+ and Mg2+ compared with samples from healthy dogs. Total muscle water and total fat content was higher in muscles from dystrophic dogs. Most muscle samples from dystrophic dogs had a type-2 fiber deficiency and an increase in number of fibers with internalized nuclei.

Hemodynamic effects of spontaneous ventilation, intermittent positive-pressure ventilation (IPPV), and high-frequency oscillatory ventilation (HFOV) were compared in 6 dogs during halothane anesthesia. Anesthesia was induced with IV thiamylal Na and was maintained with halothane (end-tidal concentration, 1.09%). During placement of catheters, dogs breathed spontaneously through a conventional semiclosed anesthesia circuit. Data were collected, and dogs were mechanically ventilated, using IPPV or HFOV in random order. Ventilation was adjusted to maintain PaCO2 between 38 and 43 mm of Hg during IPPV and HFOV. Cardiac index, aortic blood pressure, and maximum rate of increase of left ventricular pressure were significantly (P less than 0.05) less during HFOV than during spontaneous ventilation, whereas right atrial and pulmonary artery pressure were significantly greater during HFOV than during spontaneous ventilation. During IPPV, only the maximum rate of increase of left ventricular pressure was significantly less than that during spontaneous ventilation.

Serum biochemical indicators of liver function were determined in healthy, age-matched foals during the first 270 days of life. Values were compared with those of healthy adult horses and with those determined on the day of birth (< 12 hours old). Serum alkaline phosphatase, gamma-glutamyl transferase, and L-iditol dehydrogenase activities were increased during the first 2 weeks of life. Serum cholesterol, triglyceride, and total and unconjugated bilirubin concentrations peaked during this same period. During the early neonatal period (<12 hours old), globulin concentrations (mainly beta 2 and gamma fractions) were low and albumin/globulin ratios were high. However, individual values for all analytes were varied.

The use of cultured tissue has not yet become wide-spread in research involving equine disease, and this may be attributable in part to the scarcity of published reports concerning tissue culture methods for this species. We report here the isolation of equine microvascular endothelium (EMVE) from fresh omental tissue of horses and ponies. Fresh donor tissue was minced, subjected to collagenase digestion, and filtered. Cells were layered on 5% bovine serum albumin for gravity sedimentation, the bottom layer was collected, and the cells were plated onto fibronectin-coated flasks. Medium consisted of Dulbecco modified Eagle medium with 10% whole fetal bovine serum (wFBS) and 20 micrograms of endothelial cell growth supplement/ml. The EMVE grew readily in culture, had the cobble-stone morphologic feature at confluence, stained positively for factor VIII-related antigen, and metabolized acetylated low-density lipoprotein. Fibroblast and smooth muscle cell contamination was minimal in primary cell cultures, which were successfully passed and maintained in culture for 3 to 5 serial passages, using various media and substrates. Preliminary studies were undertaken to determine optimal growth conditions with a range of variables: serum concentration, extracellular matrix components, and growth factors. Optimal conditions were achieved with a minimum of 10% wFBS, and with either fibronectin or laminin as extracellular matrix substrates. The EMVE grew adequately in Dulbecco modified Eagle medium plus 10% wFBS, and the added growth factors or serum supplements did not appear necessary for growth of EMVE.

Protein profiles of whole homogenates of anconeus (slow twitch) and biceps femoris (fast twitch) muscles of clinically normal dogs and of Labrador Retrievers with hereditary myopathy (HM) were resolved on flat bed polyacrylamide isoelectric-focusing gels. Three methods of sample solubilization were performed. The solubilization buffer, with high concentrations of urea, precipitated the zwitterionic detergent, but use of the buffer containing 3% NP-40, 9.2M urea, and 0.1M arginine resulted in better resolution and stability of pH gradient. Gels of anconeus muscle from clinically normal dogs contained 2 protein bands specific to anconeus muscle, whereas gels of biceps femoris muscle from clinically normal dogs contained 3 protein bands amplified in biceps femoris muscle that were barely detectable in anconeus muscle. The staining intensity of protein bands in biceps femoris muscles from Labrador Retrievers with HM was decreased, relative to controls. The quantitative analysis of peak height ratios of biceps femoris muscle revealed significant (P less than 0.05) differences between profiles of clinically normal dogs and Labrador Retrievers with HM.

Outer membrane protein (OMP)-enriched extracts of avian strains of Pasteurella multocida were examined by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Culture medium did not have a significant effect on the OMP profiles of strains of P multocida examined; however, in vivo propagation had an appreciable effect on the OMP profile composition of the reference strain P-1059. Such bacteria, expressed several additional OMP in the 27-kD, 48-kD, 56-kD, 60-kD, 80-kD, and 94-kD molecular mass regions. These OMP were not detected in the electrophorogram of strain P-1059 grown in vitro. The OMP profiles of reference strains of the 16 serotypes of P multocida did not identify any serotype-specific protein markers. Field strains of serotype A:3 had variation in OMP profiles and did not express OMP that all were identical to that expressed by the reference strain P-1059. The live attenuated CU and M9 bacterial vaccine strains expressed strain-specific OMP markers of 48-kD and 45-kD molecular masses, respectively. These strain-specific OMP markers may be used to differentiate these strains from virulent field strains that are of the same serotype and isolated from turkeys that have succumbed to pasteurellosis as a result of vaccine-related reactions or breakdown in immunity.

Phagocytic and oxidative metabolic activities of bovine blood neutrophils were determined in the presence of glycolytic (NaF) and cytoskeletal (colchicine, cytochalasin B, and prostaglandin E1) inhibitors. Phagocytosis and postphagocytic oxidative metabolic activity, measured by nitroblue tetrazolium reduction, were determined using zymosan, Escherichia coli, Staphylococcus aureus, or Streptococcus agalactiae. Sodium fluoride (1.25 micromolar to 1.25 mM concentrations) did not significantly (P greater than 0.05) inhibit phagocytosis of S aureus and Str agalactiae, whereas phagocytosis of zymosan and E coli was significantly (P less than 0.05) inhibited only at 1.25 mM concentration. Colchicine at 1.25 nM to 1.25 micromolar conce ntrations significantly inhibited phagocytosis of zymosan and E coli, but not of S aureus and Str agalactiae. Cytochalasin B at 1.25 nM to 1.25 micromolar concentrations significantly inhibited phagocytosis of zymosan and all 3 bacteria, whereas prostaglandin E1 was noninhibitory at similar concentrations. Nitroblue tetrazolium reduction, in general, was not significantly affected by NaF and cytoskeletal inhibitors.

Lateral cecal arterial blood flow, carotid arterial pressure, heart rate, and mechanical activity of the circular and longitudinal muscle layers of the cecal body were measured in 7 conscious healthy horses during IV infusion of physiologic saline solution for 60 minutes (control), during a 60-minute IV infusion of dopamine (at dosages of 1, 2.5, and 5 microgram/kg/min), and for 60 minutes after IV infusion of dopamine. The mean values for lateral cecal arterial blood flow during IV infusion of dopamine at a dosage of either 1 or 2.5 microgram/kg/min were not significantly different from the mean values for lateral cecal arterial blood flow during IV infusion of saline solution. The mean values for lateral cecal arterial blood flow, however, were significantly greater during IV infusion of dopamine at a dosage of 5 microgram/kg/min than the mean values for lateral cecal arterial blood flow during IV infusion of saline solution. Intravenous infusion of dopamine at 1 and 2.5 microgram/kg/min did not significantly change the mean values for carotid arterial pressure. In contrast, the mean values for carotid arterial pressure were significantly less during IV infusion of dopamine at dosages of 2.5 and 5 microgram/kg/min than during infusion of saline solution. The mean values for heart rate were not significantly altered by infusion of dopamine at a dosage of either 1 or 2.5 microgram/kg/min, but infusion of dopamine at a dosage of 5 microgram/kg/min significantly increased heart rate. Intravenous infusion of dopamine at dosages of either 1 or 5 microgram/kg/min did not significantly change the mechanical activity of the circular muscle layer of the cecal body, as measured by the area under the strain gauge deflection curve. Conversely, the mechanical avtivity of the circular muscle layer of the cecal body was significantly reduced by IV infusion of dopamine at a dosage of 2.5 microgram/kg/min. This reduction of circular muscle mechanical activity by dopamine infusion was attributable to a significant decrease in the total duration of contractions. The mechanical activity of the longitudinal muscle layer was not significantly altered by infusion of dopamine at any dose. These results suggest that IV infusion of dopamine at a dosage of 5 microgram/kg/min increased lateral cecal arterial blood flow by either increasing cardiac output or dilating the lateral cecal artery, an effect most likely mediated by dopaminergic or beta-adrenergic receptors. In addition, dopamine had a biphasic effect on contractile activity of the equine cecum.

Two federally licensed attenuated live transmissible gastroenteritis (TGE) virus vaccines (an IM vaccine and an oral-IM vaccine) and 1 nonlicensed nonattenuated live TGE virus vaccine were evaluated and compared in sows free of TGE virus-neutralizing antibodies. Litters from the sows were challenge exposed at 3 and 5 days of age, and results were combined according to the vaccine administered to the sows. The survivability of pigs suckling sows vaccinated with the nonattentuated vaccine was significantly (P less than 0.01) greater than that of pigs suckling sows vaccinated with the IM attenuated vaccine, significantly (P less than 0.05) greater than that of pigs suckling sows vaccinated with the oral-IM attenuated vaccine, and significantly (P less than 0.05) greater than that of pigs suckling sows that had not been vaccinated. The differences, however, between survivability of litters from sows vaccinated with the IM attentuated vaccine or the oral-IM attenuated vaccine and that of litters from the sows not vaccinated were not significant (P greater than 0.10). The nonattenuated TGE vaccine, although giving a higher level of protection than the attenuated vaccine was eventually overwhelmed. Dexamethasone did not increase the incidence of diarrhea, and levamisole did not potentiate the lactogenic immunity in sows after given their first dose of the nonattenuated vaccine. Survivability in litters suckling sows that developed diarrhea after given their first dose of the nonattenuated vaccine was not greater than that in litters suckling sows that did not develop diarrhea. The best results were obtained when 3-day-old suckling pigs were challenge exposed with virulent TGE virus.