To differentiate Mycoplasma hyopneumoniae, the cause of mycoplasmal pneumonia in pigs, from M flocculare and M hyorbinis, an assay, using the polymerase chain reaction to amplify a segment of the 16S rRNA gene sequence, was developed. The assay was found to be useful for identification of field isolates, as well as for identification of laboratory-adapted strains. Amplification of DNA from M hyopneumoniae and M flocculare resulted in products of 200 and 400 base pairs, respectively. The DNA from M hyorbinis was not amplified. The assay was sensitive enough to detect as little as 1,000 genome equivalents of M hyopneumoniae and M flocculare DNA. Sensitivity was increased 100-fold by increasing the concentration of magnesium ion in the reaction buffer from 2 to 4 mM; however, DNA from M hyorbinis was also amplified under these conditions. The DNA from several walled bacteria and from other mycoplasmas was also tested, but none of these DNA samples was amplified, suggesting that the assay was specific for porcine mycoplasmas.

In a crossover trial, 7 healthy, 7- to 29-day-old, unweaned Finnish Ayrshire calves were given a single dose of 20 mg of tinidazole/kg of body weight, IV, and a single dose of 25 mg of tinidazole/kg orally. Blood samples were collected serially, and serum concentration of tinidazole was measured by use of high-performance liquid chromatography. Serum concentration vs time data were analyzed by use of the statistical moment theory. Terminal half-life was 394 minutes after IV administration and 524 minutes (harmonic mean) after oral administration. The corresponding system moment mean residence times were 542 +/- 61.8 minutes and 812 +/- 117 minutes (arithmetic mean +/- SD), respectively. Estimated volume of distribution at steady state and total body clearance were 0.74 +/- 0.05 L/kg and 1.37 +/- 0.13 ml/min/kg, respectively. Tinidazole was rapidly and totally absorbed from the gastrointestinal tract. Mean absorption time was 270 +/- 160 minutes, and the observed peak serum concentration was detected at 240 minutes. Bioavailability was 99.5 +/- 3.9%.

Epidemiologic modeling of the likely herd-to-herd transmission of pseudorabies virus (PRV) was developed to assess the progress and potential for the PRV-eradication program in the United States. The herd-to-herd transmission of PRV over a 20-year period (1993 to 2012) in the United States was simulated under various scenarios, which included variable program-funding levels and variable prevalences. A transition model (Markov process model) was used to predict yearly changes in herd prevalence of PRV infection. Five mutually exclusive states of nature for herds were assumed: uninfected and not vaccinated; uninfected and vaccinated; known to be infected and not vaccinated; known to be infected and vaccinated; and infected, but not known to be infected. Three prevalences for states in the United States were assumed: higher prevalence, moderate prevalence, and lower prevalence. Three funding levels were assumed: no eradication program, continued funding at the current level, and increased funding of 25%. Estimates made by an expert panel for determining probabilities in the state-transition matrices were used. A model also was developed, and was considered to be the most optimistic scenario likely under increased funding of 25%. The most optimistic estimates of the probabilities that still lay within the range of estimates made by the expert panel were used for this model. Only the optimistic transmission matrices allowed for total eradication of PRV. Using the optimistic matrices, all states in the United States of America had moved into the moderate- or low-level risk status by the year 2000. The longest time taken to achieve eradication was for the state of Iowa, where eradication was not achieved until 2012.

The cause of species difference in the susceptibility of erythrocytes to L-sorbose, and the difference in the hemolytic effect of sorbose on high potassium-containing (HK) and low potassium-containing (LK) canine erythrocytes were examined. L-sorbose was phosphorylated in canine erythrocytes, but not in human erythrocytes. Furthermore, sorbose-1-phosphate, a metabolite of L-sorbose, strongly inhibited the hexokinase of LK canine erythrocytes, but not that of HK canine erythrocytes. These results strongly indicated that inhibition of hexokinase by sorbose-1-phosphate in LK erythrocytes induced severe glycolytic limitation in these cells, resulting in hemolysis, and that HK erythrocytes are resistant to sorbose-induced hemolysis because these cells have a high hexokinase activity.

High serum alkaline phosphatase (ALP) activity is considered a sensitive marker of cholestasis in most mammalian species, including dogs. Induction of high serum ALP activity in association with cholestasis is dependent on high hepatic bile acids concentrations. Treatment of dogs with glucocorticoids also results in high serum ALP activity. The possible causal relation between serum ALP activity and bile acids concentration was investigated in dogs treated with glucocorticoids. The relation of glucocorticoid treatment to changes in the activity of individual ALP isoenzymes, alanine transaminase (ALT) and gamma-glutamyltransferase (GGT) also was investigated. Eight conditioned dogs were given 4 mg of prednisone/kg of body weight, IM, daily for 10 days. Blood samples were taken prior to treatment and on treatment days 3, 5, 7, and 10. Liver tissue was then taken from each dog. Serum total ALP activity was significantly (P < 0.05) high at day 3 in prednisone-treated dogs. Isoenzyme analysis indicated that this increase was attributable to an increase in the liver ALP isoenzyme (LALP). Significant increases in serum corticosteroid-induced ALP (CALP) and bone ALP were first observed on days 7 and 10, respectively. Serum ALT and GGT activities were significantly increased by day 5. Increased serum or hepatic tissue bile acids concentrations were not observed in prednisone-treated dogs, compared with values in 8 clinically normal (control) dogs, but were high in 3 dogs with complete bile duct ligation. Hepatic activities of LALP, CALP, and GGT were higher in prednisone-treated dogs than values in controls, indicating probable increased hepatic synthesis of these enzymes. Hepatic ALT activity was not increased. The ratio of serum to tissue LALP activity was increased in prednisone-treated dogs, compared with values in controls, indicating that LALP may have been preferentially released into serum. There was no difference in the ratio of serum to liver GGT activity between prednisone-treated dogs and controls. The LALP and GGT ratios were increased in bile duct-obstruction dogs. It was concluded that, although LALP is the principal ALP isoenzyme in serum during the first 10 days of prednisone treatment, hepatic bile acid concentrations are not increased and, therefore, are not likely to be responsible for induction and release of ALP into serum. Prednisone may, therefore, be directly responsible for induction of ALP activity in dogs treated thusly.

Recombinant equine interferon-beta 1 (reqIFN-beta 1) induces an antiviral state in blood mononuclear cells (BMC) of horses. Maximal protection against replication of vesicular stomatitis virus is achieved 6 hours after treatment with IFN in vitro and in vivo. Duration of the protective effect depends on the dose of IFN in vitro and in vivo. Availability of reqIFN-beta 1 in cultures of BMC for up to 48 hours does not prolong the antiviral state. The protective effect on BMC after treatment with IFN has similar duration in vivo and in vitro. Monitoring of the effect of IFN in vivo is, thus, simplified because the antiviral state may be recorded by testing cells twice (ie, before and 6 hours after application of interferon). All further tests may be performed in vitro. Multiple administrations of reqIFN-beta 1 do not prolong duration of the protective phases after each administration. Duration of the antiviral state depends only on the dose of reqIFN-beta 1.

An antigen extract of Dictyocaulus viviparus was analyzed by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the antigen-recognition patterns of serum antibody from cattle not infected, cattle infected with D viviparus, and cattle with unknown history of D viviparus were analyzed by the use of ELISA and western blotting techniques. Cross-reactive antibody-recognition patterns were determined by comparing western blots of D viviparus-positive sera with blots of D viviparus-negative sera obtained from cattle singly infected with Bunostomum phlebotomum, Cooperia oncophora, C punctata, Nematodirus helvetianus, Oesophagostomum radiatum, or Ostertagia ostertagi. Five antigen bands unique to D viviparus were identified, and their frequency of appearance in western blots of sera from verified D viviparus-positive and -negative cattle, and sera from cattle exposed to the parasite, but with unknown D viviparus immune status, were determined. Of the 5 antigens unique to D viviparus, 29- and 19-kd bands had the highest frequencies of reaction (45.9 and 59.0%, respectively) with the test sera. These bands had strong reactivity with sera containing antibodies to D viviparus and did not react with the heterologous sera. We conclude that the 29- and 19-kd antigens may be useful for developing an improved serodiagnostic test for D viviparus infections in cattle.

Effects of differential ventilation on gas exchange were studied in 7 isoflurane-anesthetized, laterally recumbent horses, and were compared with effects of conventional ventilation, using similar minute volume. A tracheal tube-in-tube intubation technique allowed each lung to be connected separately to an anesthetic circle system with a ventilator. Two distribution patterns of tidal volume were investigated; half the tidal volume was distributed to each lung and two-thirds the tidal volume was distributed to the dependent lung. Effects of the combination of these patterns with positive end-expiratory pressure (PEEP) of 10 and 20 cm of H20 to the dependent lung were investigated. Differential ventilation maintained PaCO2, but significantly increased PaO2, from 180 to 270 mm of Hg (+44%) and decreased shunt perfusion from 22 to 19% (-15%), regardless of the distribution pattern used. Mean airway pressure was lower than the value detected during conventional ventilation. The combination of differential ventilation with selective PEEP was followed by a decrease in PaCO2 and further increase of PaO2 and decrease of shunt, which were similar for both distribution patterns. Effects of PEEP of 20 cm of H2O were more pronounced than those of PEEP of 10 cm of H2O. Owing to the combined effects of differential ventilation and selective PEEP, PaO2 increased to 399 mm of Hg and shunt decreased to 15%. This represents increase of 112% and decrease of 33% respectively, compared with values for conventional ventilation. Mean airway pressure increased maximally to 23 cm of H2O, which was 11 cm of H2O greater than the value for conventional ventilation. During differential ventilation, alveolar dead space in the dependent lung became greater than that in the nondependent lung and maximum was 39%. There were no significant changes in arterial blood pressure. Beneficial effects on gas exchange can be explained by improved matching of ventilation and perfusion, possibly attributable to reopening of previously dosed units in the dependent lung.

An ELISA was developed to detect antibodies to the 41-kd flagellin (P41) of Borrelia burgdorferi in serum obtained from cattle. Absorption studies, immunoblot analysis, immunoelectron microscopy, and correlation of results of the P41-ELISA and the P39-ELISA as well as measurement of the antibody to P41 in calves challenge-exposed with Borrelia theileri were used to assess the specificity of the P41-ELISA. Antigens derived from Escherichia coli, Leptospira interrogans serovar hardjo, and B burgdorferi were used for absorption studies and immunoblot analysis. Antibodies to P41 of B burgdorferi cross-reacted with antigens of E coli, but were not cross-reactive with L hardjo. A value 3 SD higher than the mean of the negative-control population of cattle was defined as the minimum value cutoff value) for a positive result by the P41-ELISA. Use of this value for classification of test results reduced the predicted rate of false-positive results attributable to E coli cross-reactivity to 1%. Immunoblot analysis revealed that test-positive serum from cattle reacted mainly with 41-, 39-, 34-, and 31-kd proteins of B burgdorferi, as well as several smaller proteins. Immunoelectron microscopy revealed that serum from cattle that was test-positive by the P41-ELISA bound to the flagellin and outer membrane of B burgdorferi. Results of absorption studies, immunoblot analysis, and immunoelectron microscopy were correlated and indicated that serum from cattle that was test-positive by P41-ELISA had stronger reactivity to B burgdorferi antigens than to antigens of E coli or L hardjo. The concentrations of antibodies measured by P41-ELISA and P39-ELISA testing were highly correlated [R(2)=0.78]. Calves challenge-exposed with B theileri also had test-positive results by the P-41-ELISA as early as 2 weeks after exposure, but serum antibody concentrations decreased to prechallenge-exposure concentrations by 9 weeks after exposure. We concluded that the P41-ELISA was useful as a screening method to detect B burgdorferi infections in cattle.

Sheep given powdered Ferula communis variety brevifolia at dosage of 2.5 g/kg of body weight/d for 15 days developed classical clinical signs of intoxication: anorexia, somnolence, apparent weakness, and hemorrhage. Marked reduction of vitamin K-dependent coagulation factors and prolongation of prothrombin time and activated partial thromboplastin time were consistent with presence of ferulenol, a toxic coumarinic factor in the plant. Changes induced in the coagulation system developed by the second day of plant administration and were normal within 4 days after dosing was stopped. There was no evidence of primary liver damage or platelet malfunction. Of 6 intoxicated sheep, 2 died with only minimal evidence of hemorrhage.