Actinobacillus (Haemophilus) pleuropneumoniae plasmids were characterized and classified. They were isolated from A pleuropneumoniae strains different in serotype, year isolated, or location from which isolated. Six of 8 plasmids encoded streptomycin (Sm) and sulfonamide (Su) resistance (SmSu). One of the other plasmids, pVM105, encoded ampicillin (Ap) resistance and another, pHMO, encoded no drug resistance. All SmSu plasmids were transferred to Escherichia coli strains by transformation. Among them, pABO and pMS260 were 8.1 kb and incompatible with each other; they were stable in E coli. The other SmSu plasmids, pHM1, pVM104, pVM106, and pKD25, were 4.3 kb and did not replicate stably in E coli. The former SmSu plasmids were mobilized in E coli strains by a plasmid RP4, which belonged to incompatibility (Inc) group P, but the latter plasmids were not. Further, each 8.1-kb SmSu plasmid and each 4.3-kb plasmid had the same respective restriction pattern. These results indicated that there were at least 2 types of SmSu plasmids in A pleuropneumoniae. The 2 types were classified in 2 groups: Hl(pMS260 and pABO) and H2(pHM1, pVM104, pVM106, and pKD25). The Hl and H2 plasmids belonged to a different Inc groups, and H2 plasmids belonged to a different Inc group from that of pHMO and pVM105.

On the basis of serologic test results and isolation of leptospires from mature cattle, distribution and prevalence of Leptospira interrogans serovars and genotypes were compared by state and region of the United States. Relationships between isolation rate and month of sample collection, mean regional temperature, and mean regional precipitation were examined. Isolation rate and seroprevalence were significantly (P < 0.001) higher for southeastern, south central, and Pacific coastal regions than for other regions of the United States. Isolates of genotypes hardjo-bovis A and kennewicki A and B, and of serovar grippotyphosa appeared to be randomly distributed. Genotype hardjo-bovis B isolates came from a southern area of the country that extends from Georgia to New Mexico. To the authors' knowledge, this is the first recorded isolation of serovar hardjo from Hawaii. Although significant relationship was not documented between isolation rate and month or season of the year, seroprevalence for summer, fall, and winter was significantly (P < 0.001) higher than that for spring. Regional isolation rate was related more to mean temperature (r = 0.83; P < 0.05) than to mean precipitation amount (r = 0.34; P > 0.50).

Two recently developed direct methods, radioassay-125I-labeled hyaluronic acid binding protein (125I-HABP)- and high-performance liquid chromatography (HPLC), were used to assess and compare the concentration of hyaluronate (HA) in synovial fluid of horses. Also determined were changes in the HA concentration in an experimental treatment model involving physiologic saline solution (PSS)-irrigated or methylprednisolone acetate-injected tarsocrural joints of clinically normal horses. Serum HA concentration was determined simultaneously, using the 125I-HABP assay. Synovial fluid HA concentration values obtained by use of the HPLC method were approximately double the values obtained by use of 125I-HABP assay. Correlation (r = 0.819) between the 2 methods was highly significant (P < 0.001; linear regression analysis) for all samples studied and for various experimental subgroups. When pure HA standards were used, correlation between the 2 methods was close to 1 (r = 0.965; P < 0.001), with higher values obtained by use of the 125I-HABP assay. It is suggested that the HA binding protein derived from endogenous cartilage proteoglycan interferes with the 125I-HABP assay on synovial fluid, resulting in excessively low values, compared with those obtained using the HPLC procedure. Intra-articular injection of methylprednisolone acetate significantly (P < 0.01) increased synovial fluid HA concentration at 24 hours after injection. Increase was also detected after PSS irrigation, but owing to wide intersubject variation, this increase was not significant. The HPLC procedure, which provides simultaneous information about the concentration and degree of polymerization of HA, is recommended for the study of synovial fluid, whereas the 125I-HABP assay is more suitable for serum HA analysis.

Effects of the endophyte Acremonium coenophialum in tall fescue on pregnant mares and foal viability were evaluated. Twenty-two mature pregnant mares were randomly chosen to graze either Kentucky-31 tall fescue that was free from A coenophialum (endophyte-free, EF) or tall fescue infected with A coenophialum (endophyte-present, EP) after the first 90 days of pregnancy through parturition. Concentrations of pyrrolizidine and ergopeptine alkaloids were significantly greater in EP grass, compared with EF pasture. Ten of 11 mares grazing EP pasture had obvious dystocia. Mean duration of gestation was significantly greater for the EP group, compared with the EF group. Foal survivability was severely reduced among mares grazing Ep fescue with only 1 foal surviving the natal period. Udder development and lactation were low in mares grazing EP grass. The absence of clinical problems in mares grazing EF grass implicated the endophyte as the causative agent of reproductive problems and perinatal foal mortality in pregnant mares grazing endophyte-infected fescue grass. Caution should be exercised in allowing pregnant mares to graze pastures infected with the endophyte A coenophialum.

Estrogen receptors were measured in normal canine lymph nodes and neoplastic tissue from dogs with lymphoma, using a commercially available [3H]estradiol dextran-coated charcoal assay. Using the same assay, estrogen receptors were detected in the positive-control tissues--dog uterus, rat uterus, and lyophilized bovine uterus. Specific binding of [3H]estradiol was not detected in rat skeletal muscle or in any of the canine lymphoid tissues, indicating that the specimens did not contain estrogen receptors.

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.

The purpose of this study was to evaluate a commercial enzyme-linked immunosorbent assay (ELISA) for human von Willebrand factor antigen (vWF:Ag) with respect to its potential value in quantitating the protein in canine plasma. The assay was a sandwich technique using F(ab')2 fragments specific for von Willebrand factor (vWF) and a peroxidase conjugated rabbit anti-vWF second antibody, with a microplate as the support surface. Canine plasmas were assayed by ELISA, and by Laurell electroimmunoassay (EIA), our reference methodology. The ELISA had a within-day variation of 1.21-4.44% and a between-day variation of 0.85-4.88% depending on the level of vWF:AG. The sensitivity of the assay was less than 0.1% vWF:AG. The range of vWF:AG concentrations in plasmas from 24 clinically normal dogs compared favorably with the range for the same plasmas when assayed by EIA (ELISA = 60-152% of normal; EIA = 50-142% of normal). In 121 canine plasmas with vWF:AG concentrations (as assessed by EIA) ranging from undetectable levels (< 6% of normal) to 142% of normal, there was good correlation with measurements made by ELISA (correlation coefficient = 0.835). It was concluded that this commercial ELISA technique could be used to provide reliable, same-day measurements of canine plasma vWF:AG. Since it requires no special equipment other than a microplate reader and washer it is particularly suitable for laboratories lacking the electrophoretic expertise or equipment required for EIA.

Few safe and effective anesthesia regimens have been described for use in rabbits, partially because of the susceptibility of this species to sometimes fatal respiratory depression. Although inhalant anesthetics are generally safer than injectable anesthetics, their use may be limited by lack of equipment or facilities. This study was conducted to compare effects of several injectable anesthetics in rabbits on response to noxious stimuli, heart rate, respiratory rate, and rectal temperature. Six injectable anesthetic combinations were administered to rabbits: xylazine-ethyl-(l-methyl-propyl) malonyl-thio-urea salt (EMTU), ketamine-EMTU, xylazine-pentobarbital, xylazine-acepromazine-ketamine (XAK), ketamine-chloral hydrate, and ketamine-xylazine. All combinations induced a depression of respiratory rate. Although rectal temperature values were reduced to some degree in each group, the most profound hypothermia was induced by XAK. The combination that induced the longest duration of anesthesia was XAK. It was concluded that XAK was preferable for longer periods of anesthesia (60 to 120 minutes), although it induces severe hypothermia. For short periods of anesthesia, xylazine-pentobarbital, xylazine-EMTU, or ketamine-xylazine were deemed adequate; however, xylazine-EMTU induced the best survivability and consistency.

An Escherichia coli bacterial prostatitis was experimentally induced to determine the effect of bacterial infection on prostatic tissue zinc concentrations in castrated and gonadally intact male dogs. Five of the 22 mixed-breed dogs (group 1) had no culture evidence of infection 2 weeks after the instillation of bacteria into the prostate gland. The remaining 17 infected dogs were allotted to 2 groups; 1 group of dogs was subjected to castration (group CA, 7 dogs), and the other group of dogs was subjected to sham operation (group SO, 10 dogs). The groups were divided into groups of dogs with prostatic infection at necropsy (groups CA-I and SO-I), and those dogs without prostatic infection at necropsy (groups CA-N and SO-N). Urine, prostatic fluid, and prostatic tissue (week 0, 7, +/- 12) specimens were obtained for bacteriologic culturing to determine whether prostatic infection was present. Prostatic tissue was obtained at necropsy (week < 6, 7, or 12) for analysis of zinc concentration by atomic absorption spectrophotometry. The logarithmic mean prostatic tissue zinc concentrations were compared between groups. Group CA had a significantly lower prostatic zinc concentration than all other groups. Zinc concentrations were not statistically different between any of the other groups. Castration did decrease the prostatic tissue concentration of zinc, a known natural antibacterial factor. However, resistance to infection and resolution of infection were not correlated with prostatic tissue zinc concentrations in this experimental model.

The DNA fragments representing the entire short unique region and part of the repeat sequences of the equine herpesvirus type-1 genome were cloned into plasmid vectors. The approximate positions of the junctions between the short unique region and the inverted repeats were then located by restriction endonuclease mapping. Two open reading frames coding for potential glycoproteins have been identified within the short unique region, using DNA sequence analysis. The predicted amino acid sequences of these open reading frames had extensive homology to the herpes simplex virus glycoproteins gE and gI and the related glycoproteins of pseudorabies virus and varicella-zoster virus.