Restriction endonuclease patterns of genomic fragments separated by use of pulsed-field gel electrophoresis were used to differentiate Brucella abortus strain RB51, a rifampin-resistant mutant of the standard virulent strain 2308, from other brucellae. Results were compared with results obtained by use of standard methods for characterizing brucellae. Electrophoretic patterns of the ATCC type strains allowed identification of the strains to the level of species. Genomic profiles of B abortus biovars 1, 2, and 4 were similar, as were those of biovars 5, 6, and 9. The profile of biovar 3 was similar to that of biovars 5, 6, and 9, except for a missing band at 93 kb and additional bands at 65 and 67 kb. A different fingerprint was detected in B abortus strain RB51, using the pulsed-field gel electrophoresis patterns of genomic DNA digested with restrictive endonuclease Xba I. The profile of B abortus strain RB51 contained a band at 104 kb, as opposed to a 109-kb fragment within profiles of B abortus isolates from naturally infected cattle, bison, and elk. Despite known biochemical and biological differences between RB51 and its parent strain (2308), restriction endonuclease analysis results were similar.

The metabolic responses of equine articular cartilage to incubation with bacterial lipopolysaccharide (LPS) were studied, using explant cultures of articular cartilage obtained from the metatarsophalangeal joints of 15 horses, age of which ranged from 3 months to 20 years. For comparison, explants were also established from the metatarsophalangeal joints of 3 calves. Explants were cultured for 3 days in medium containing various concentrations of LPS from 0 (control) to 100 microgram/ml. Glycosaminoglycan (GAG) released during the 3-day incubation was determined by a spectrophotometric assay, using the dye 1,9-dimethylmethylene blue. Newly synthesized GAG content was assayed by measuring [35S]sulfate incorporation during a 3-hour pulse labeling period. In addition, prostaglandin E2 (PGE2) synthesis was quantified, using a [3H]PGE2 radioimmunoassay kit and magnetic separation. Finally, explants from 3 animals were used to evaluate the effect of supplementing culture medium with 5% serum on the response of explants to LPS, and explants from 1 horse were used to compare responses to stimulation with LPS derived from 2 bacterial sources. Equine explants cultured with bacterial LPS had a dose-dependent decrease in synthesis and increase in release of GAG, and these responses were significantly (P < 0.0001) greater in explants from younger horses. In addition, equine explants had a significant (P = 0.0001) dose-dependent increase in concentration of PGE2 released into the culture medium in response to incubation with LPS. Comparison of data for GAG synthesis from equine and bovine explants revealed a significant (P = 0.025) difference in responsiveness to LPS between the 2 species. Equine explants tended to have a greater suppression of GAG synthesis in response to incubation with increasing concentrations of LPS than did age-corrected bovine samples. However, similar analysis of data on GAG release did not indicate any difference in sensitivity between the 2 species for this response. There was no evidence that the presence or absence of serum supplementation or the use of LPS derived from different bacterial sources made a significant difference in the response of explants to incubation with LPS.

High-resolution computed tomography (HRCT) was performed in 21 isolated animal lungs, from 4 mammalian species (pigs, rabbits, dogs, sheep). Gross and subgross central and peripheral lung morphology was determined by HRCT. Three distinct types of lungs can be identified, principally based on the extent of interlobular septal development; the relationship of major vessels to airways; and the thickness of the visceral pleura. Type-I lung is found in pigs, sheep, and cattle; type-II lung is found in rabbits, dogs, cats, and monkeys; and type-III lung is found in human beings and horses. These mammalian lungs were compared with human lungs. The potential use of HRCT to investigate specific human lung diseases in the aforementioned species also was considered.

To provide information about oncogenes for molecular biological studies of tumors in domestic animals, theproto-oncogenes homologous to the c-myc, c-erbB-2, c-ros-1, c-yes-1, v-myc, v-Ki-ras, and v-Ha-ras oncogenes of genomic DNA in cattle, horses, pigs, dogs, cats, and chickens were investigated by Southern blot hybridization. High molecular weight genomic DNA in each of the animals contained proto-oncogenes that had a certain homology with the oncogenes used, but the extent of nucleotide homology of the proto-oncogenes differed in number and molecular weight: ie, 1 or 2 bands at 1.6 to 22.0 kilobase (kb) in the c-myc probe, 1 or 2 bands at 1.1 to 16.0 kb in the c-ros-1 probe, 1 to 3 bands at 0.7 to 23.0 kb in the c-erbB-2 probe, 1 to 4 bands at 0.6 to 18.0 kb in the c-yes-1 probe, 1 to 3 bands at 1.6 to 30.0 kb in the v-myc probe, 1 to 7 bands at 1.0 to 36.0 kb in the v-Ki-ras probe, and 1 to 4 bands at 1.0 to 27.0 kb in the v-Ha-ras probe. Furthermore, signal strength of each band, as determined by autoradiography, was not always the same for each probe in the various animals. Our findings indicate that these proto-oncogenes are well conserved with species specificities in each animal.

In mammalian species studied previously, pepsinogen consisted of biochemically different groups of isozymogens. By use of gel filtration chromatography and electrophoresis, we isolated a predominant pepsinogen from the gastric mucosa of a horse. Peptide mapping with V8 protease revealed differences with its porcine homologue. However, porcine and equine pepsinogens, when activated to pepsin, had a similar pattern of activity when hemoglobin was used as substrate. Those results suggest that differences must exist in the primary structure of the pepsinogens of the 2 species.

Ovine progressive pneumonia is caused by a lentivirus of known infectivity only for sheep and goats. Virus susceptibility of 11 other species of animals was examined. Species included cattle, chickens, deer, dogs, goats, hamsters, horses, mice, pigs, rabbits, and rats. Of these species, only goats and rabbits could be experimentally infected with the virus. The infection in rabbits was acute, and virus did not persist or induce antibody production as it does in sheep and goats. Sera obtained from several people working in close contact with the virus and from several wild species, with unknown exposure history, were tested for antibodies to viral antigens. All results were negative. Knowledge of the host range of this virus is important for scientific studies and for virus eradication programs.

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.

Disposition kinetic variables of HI-6, a bispyridinium oxime, have been determined in mice, rats, rabbits, Rhesus monkeys, Beagles, sheep, and human beings. The drug has a short half-life, small apparent volume of distribution and high body clearance in these species, and is eliminated mainly by renal excretion. Using regression analysis and double logarithmic plots of the pharmacokinetic variables vs body weight of the various species, it was observed that body (systemic) clearance is the pharmacokinetic variable to use for interspecies comparison of elimination of the drug. The allometric exponent denoting the proportionality of body clearance of HI-6 to body weight of the 7 species studied was 0.76, which may be related to the renal excretion process for the drug. The apparent volume of distribution was similar (260 to 304 ml/kg of body weight) in the various species. The results indicate that volume of distribution, body clearance, and with less confidence, half-life might be used for interspecies scaling and for predicting these variables in other mammalian species. On the basis of the pharmacokinetic variables in selected species (rats and mice excluded), IV administration of III-6 at a dosing rate of 20 to 25 mg/kg at 4-hour intervals should provide an average steady-state plasma concentration of 16 to 20 micrograms/ml in domestic animals. The short half-life of III-6 precludes increasing the dosage interval.

Replication of bluetongue virus (BTV) in leukocytes from the blood of sheep, cattle, elk, and mule deer inoculated with BTV serotype 10 or 17 was assessed by immunocytochemical staining and dot blot northern hybridization to determine if differences in the prevalence of infection in this blood fraction might account for the differences in clinical disease among these species. Viremia was confirmed by virus isolation in all inoculated animals. Analysis of leukocytes with monoclonal antibodies specific for BTV proteins revealed low numbers of infected leukocytes in only 2 sheep 8 days after inoculation with BTV serotype 10. Most of the cells expressing BTV were identified morphologically as monocytes; approximately 10% of infected cells were lymphocytes. Bluetongue virus was not detected by use of dot-blot hybridization on samples of blood. Our results suggest that differential infection of leukocytes does not account for the pronounced differences in clinical signs and pathologic changes among ruminants.

Isoelectric focusing was performed on the soluble proteins of whole-body and excretory-secretory products (ESP) of Fasciola hepatica and Fascioloides magna. Adult F hepatica flukes were recovered from experimentally infected sheep and ESP obtained from the flukes; portions of liver were cut and frozen at -70 C. Fascioloides magna adults were collected from naturally infected white-tailed deer and ESP obtained; portions of liver were collected from noninfected white-tailed deer. Adult flukes and their host tissues were homogenized and centrifuged; protein concentrations with their ESP were determined and adjusted to < 2.50 mg/ml. Seven ESP samples from F hepatica and 1 from Fascioloides magna were subjected to isoelectric focusing with the 2 species of fluke and their respective host liver homogenates. After separation, gels were stained with silver and scanned on a laser densitometer. Protein banding patterns of the 2 species of flukes were dissimilar. In the pH range of 3.5 to 9.6, the body protein had approximately 30 peaks and ESP about 23 peaks in both species. Overall banding patterns of the body protein and ESP of both species were distinct from those of respective host tissues. Of the peaks reported as dominant, 3 of the body protein and 2 of ESP were shared between the 2 species. Fascioloides magna had more dominant peaks than F hepatica. This technique of soluble protein isoelectric focusing is simple and reproducible, and the 2 fluke species can easily be differentiated by this technique, as well as by morphologic characteristics.