Sera from cats with naturally acquired and experimentally induced feline immunodeficiency virus (FIV) infections were tested by immunoblot analysis, radioimmunoprecipitation assay (RIPA), and a complex trapping/ blocking ELISA. In sequentially obtained samples from experimentally inoculated cats, antibodies against the envelope protein gpl20 and the core protein pl5 were the first to appear, as indicated by results of RIPA, using lysates of FIV-infected lymphocytes. Antibodies could be detected as early as 2 weeks after infection, followed by a response against p24, p43, and p50. By immunoblot analysis, p24 and pl5 were the first proteins detectable between postinoculation weeks 3 and 5; an anti-envelope response was never found by use of this assay, but was found by RIPA. Using the latter test, most sera of naturally infected cats were found to recognize the major core protein p24 in addition to 1 or more minor core proteins. All 40 sera tested precipitated the envelope protein; 3 reacted exclusively with it. A complex trapping/blocking ELISA was developed to quantitate the anti-p24 response. Sera from healthy FIV-infected cats were shown to have higher anti-p24 titer than did those from diseased cats.

Effects of analog filter frequency on brain stem auditory-evoked potentials (BAEP) were investigated in 7 non-sedated dogs. The BAEP were recorded successively at various low-pass (LP) and high-pass (HP) filter frequency settings. The analog filters had a rolloff of 6 dB/octave. Decrease of LP filter frequency from 30 khz to 100 Hz caused prolongation of the peak latency and reduction of the peak-to-peak (from a positive peak to the following trough) and absolute (from a positive peak to the baseline) amplitudes for aU peaks, except the peak latency for P5 and the absolute amplitude for P4. Changes in these variables were statistically significant (P < 0.05) at different cutoff frequencies specific for the individual peaks. The inter-peak latency between P1 and P4, and P4/P1 peak to-peak amplitude ratio were not changed significantly. At the lowest LP filter frequency of 100 Hz, positive peaks (fast waves) seemed to be superimposed on a slow positive wave (slow wave). In contrast, increase of HP filter frequency from 0.53 to 160 Hz did not result in significant changes for any peaks, except for reduction in the absolute amplitude of P4. The various effects of LP filter frequency and negligible effects of Hp filter frequency on individual peaks may be attributable to their frequency composition and/or elimination of the slow wave at higher HP filter frequency settings. On the basis of our results, LP filter setting of 3 kHz and HP filter setting of less than or equal to 53 Hz are recommended for recording of BAEP in dogs. These settings sufficiently attenuate unwanted high-frequency artifacts, are adequate for recording of fast and slow waves, and have only slight effects on configurations, peak latencies, and amplitudes.

Gene frequencies of RBC antigens were determined in Holsteins and Colombian (criollas) cattle living at 3,000 m, and in cattle descended from fighting bulls (Vacas de lidia) living at 2,500 m. These frequencies were compared with those of Holsteins, cattle native to Florida (scrub cattle), longhorns, and native cattle from Brazil (caracu cattle) living at sea level. The criollas, Vacas de lidia, scrub cows, longhorns, and caracu are descendants of original Iberian stock introduced to the Americas. We found that despite common ancestry (scrub cattle, longhorns, criollas, and caracu), genetic differences may have been derived through years of demographic isolation. The most remarkable blood-group differences were found in the high prevalence of the B system phenogroup (heritable group of antigenic factors) BQA'G'34 in the Vacas de lidia, and of the S system phenogroup U1H' in these cattle and in caracu. Furthermore, the gene frequencies differed in the Holsteins maintained at moderately high altitude (descended from Holsteins kept at sea level), and may have been reflective of the need to adapt to moderately high altitude and chronic hypoxemic conditions. Blood group polymorphism was found in all groups of cattle, although it was reduced in the Vacas de lidia, possibly because their breeding has been carefully controlled and they appear to be highly inbred.

Dialyzable lymph node extracts (DLE) containing transfer factor prepared from calves sensitized to Mycobacterium paratuberculosis and keyhole-limpet hemocyanin (KLH) were administered to 4 adult cows with chronic paratuberculosis. Cutaneous delayed hypersensitivity, lymphocyte blastogenesis, monocyte migration-inhibition, and lymphoblast proliferative capacity as a reflection of interleukin-2 (IL-2) activity were measured in response to M bovis purified protein derivative, johnin, and KLH before and after treatment with DLE. Change in cutaneous delayed hypersensitivity was not evident after DLE treatment. Alterations in histologic features of pre- and posttreatment sections of ileum and mesenteric lymph nodes were not detected. Lymph node extract treatment significantly (P < 0.05) increased IL-2 activity and migration-inhibition in response to johnin and KLH in vitro. Treatment had no effect on lymphocyte blastogenesis. The data indicate that cattle with chronic paratuberculosis may benefit from DLE treatment, by virtue of increased IL-2 activity, and that effects of DLE are at least partially mediated by an increase in IL-2 activity.

The mean area and minimal diameter of 3 histochemically determined myofiber types (1, 2A, and 2B; myosin ATPase in acid buffer) were calculated in middle gluteal muscle biopsy specimens from 62 stallions, 47 Andalusians and 15 Arabians, ranging in age from 6 to 12 years. Fourteen Andalusians and 7 Arabians were untrained, and the remainder were actively endurance-trained. The 6-month training schedules involved walking, slow trotting, and cantering. Fourteen Andalusians were moderately endurance-trained, whereas the other 19 Andalusians and 8 Arabians were strongly endurance-trained. Significant differences were not recorded between untrained and endurance-trained Arabians with respect to the area (type 1, 3,194 +/- 869 micrometers(2) and 3,150 +/- 370 micrometers(2); type 2A, 3,819 +/- 890 micrometers(2) and 3,380 +/- 356 micrometers(2); and type 2B, 4,872 +/- 962 micrometers(2) and 4,417 +/- 646 micrometers(2) or minimal diameter (type 1, 52.2 +/- 7.4 micrometers and 52.8 +/- 3.1 micrometers; type 2A, 58.1 +/- 6.7 micrometers and 55.0 +/- 2.8 micrometers; and type 2B, 65.3 +/- 6.4 micrometers and 63.4 +/- 4.3 micrometers) of the 3 fiber types, nor between untrained and endurance-trained Andalusians with respect to the area (untrained, 3,990 +/- 690 micrometers(2) moderately endurance-trained, 3,882 +/- 347 micrometers(2); and strongly endurance-trained, 3,758 +/- 510 micrometers(2)) and minimal diameter (untrained, 58.1 +/- 4.7 micrometers; moderately endurance-trained, 59.7 +/- 2.7 micrometers; and strongly endurance-trained, 58.7 +/- 4.5 micrometers) of 2A fibers. Moderately endurance-trained Andalusians had larger 2B fibers (area 18.6%; minimal diameter 14.3%) than untrained Andalusians, and the minimal diameter of type-1 and type-2B fibers was greater in strongly endurance-trained Andalusians than in untrained Andalusians (9.5% for type 1; 10.0% for type 2B). These results suggest minimal effects of endurance training on the myofiber size of adult Andalusians and Arabians, but a tendency toward increased type-1 and -2B fiber size was found for Andalusians.

Quantitative immunodiffusion in one dimension was performed in 6-mm Duran tubes containing a 1% Nobel agar solution and various dilutions of antisera. A series of dilutions of pure myoglobin in equine sera as well as plasma from horses with rhabdomyolysis were tested. Standard curves were prepared of the migration distance of the formed precipitate from the meniscus of the gel after 3, 6, 12, and 24 hours. The clearest line of precipitate was formed with a 1:20 dilution of antisera in agar. Standard curves were nonlinear and plasma myoglobin could be detected at 2 micrograms of myoglobin/ml or greater. The test was optimal, with an error of 5.6%, when read at 24 hours at approximately 25 C. Tubes with agar could be stored for 6 months at 4 C without affecting the accuracy of the test. The specificity of myoglobin for skeletal or cardiac muscle, and its rapid clearance from serum after muscle necrosis, make it ideally suited for evaluating acute muscle damage and for testing the susceptibility of horses for rhabdomyolysis following an exercise test.

Contact wide-field specular microscopy was performed on eyes of 16 healthy dogs after tissue plasminogen activator at a concentration of 25 microgram/100 (group 1, n = 8) or 50 microgram/100 microliter (group 2, n = 8) was injected into 1 anterior chamber of each dog. The contralateral eye served as a nontreated control. Applanation tonometry was used to measure intraocular pressure in both eyes for up to 168 hours. By use of computerized morphometric analysis and pachymetry, changes from baseline values in endothelial cell density, cell morphologic features, and corneal thickness were evaluated at postinjection, hours 24, 48, and 168. Significant mean differences in intraocular pressure were not detected between treated eyes of group-1 dogs and those in group 2 at designated times, or between treated and nontreated eyes of dogs in either group. Mean corneal thickness of treated and nontreated eyes was similar in both groups through postinjection hour 168. Changes in mean percentage of endothelial cell sides were observed only in treated eyes of group-2 dogs, with the mean percentage of hexagons at postinjection hour 168 decreasing by 18%, a decrease that was significantly (P < 0.05) greater than the decrease in nontreated eyes. The mean percentage of 6-sided cells in treated eyes of group-2 dogs was significantly (P < 0.05) less than that in treated eyes of group-1 dogs at postinjection hour 168.

Experimental and field trials were conducted to evaluate an ELISA for its ability to detect Trichinella-infected domestic swine and to compare ELISA results with muscle-digestion test results. The ELISA used was a commercial double-antibody kit, containing an excretory-secretory antigen, and was evaluated principally for epidemiologic use. Experimentally induced infection in swine (4 groups of 3 pigs each; inoculated with 0, 50, 500 or 5,000 larvae) was detected as early as postinoculation week 4, with seroconversion of all inoculated swine by postinoculation week 8. The rate of seroconversion appeared to be by initial larval dose, time after inoculation, and immunocompetence of the individual host. Determination of antibody kinetics generally revealed rapidly increasing antibody titer, followed by its steady decrease in most pigs. Once seropositive, however, all pigs remained seropositive for the duration of the 10-week study. Presence of muscle larvae was confirmed in all infected pigs at termination of the study. We recognize that the experimental conditions may not be truly representative of those under which natural infection develops in pigs; however, the ELISA detected an infected pig with muscle larval density of 0.87 larvae/g of tissue. Results of a field trial (n = 310) indicated no muscle digestion test-positive pigs (35 g of diaphragm muscle digested/pig), but 3 samples tested positive by ELISA for specificity of 99.0%.

The purpose of this study was to experimentally reproduce swine infertility and respiratory syndrome (SIRS). Six multiparous sows were intranasally inoculated at 93 days of gestation with lung homogenates from clinically affected pigs, and 3 additional sows were similarly inoculated with a virus isolated in cell culture from the lung homogenate (SIRS virus, isolate ATCC VR-2332). Inoculated sows developed transient anorexia, farrowed up to 7 days prematurely, and delivered a mean of 5.8 live pigs and 6.0 dead fetuses/litter. Clinical signs of disease were not observed in 3 sham-inoculated control sows that delivered a mean of 12.7 live pigs and 0.3 stillborn fetuses/litter. The sirs virus was isolated from 50 of 76 live-born and stillborn fetuses from the 9 infected fitters. Virus was not isolated from 26 autolyzed fetuses or 15 control pigs. Six of 9 inoculated sows developed neutralizing antibodies to SIRS virus. The reproductive effects found in these experiments were identical to those found in field cases. On the basis of our findings, virus isolate ATCC VR-2332 causes the reproductive failure associated with SIRS.

The scavenging of superoxide radicals by endogenous and therapeutically administered superoxide dismutases may prevent superoxide-mediated oxidative stress leading to lipid peroxidation, membrane lysis, and cell death in a wide variety of normal and pathologic states. Simple inorganic manganous salts such as MnCl2 also have superoxide dismutase-like activity and are extremely inexpensive, compared with enzymatic superoxide dismutase preparations. In this study, we explored the use of Mn salts as antioxidant drugs. We used the percentage of inhibition of nitroblue tetrazolium reduction by superoxide as a measure of the amount of superoxide dismutase-like activity. We found concentration-related increases in superoxide scavenging activity in simple buffer solutions upon addition of 1.25, 2.5, and 5.0 microM MnSO4. To determine whether Mn salts can inhibit oxidative damage in tissues, we used an in vitro model of lipid peroxidation in ischemic and reoxygenated rat liver slices. Concentrations of 10, 100, and 1000 micromoles MnCl2/L of buffer significantly decreased indicators of lipid peroxidation believed to be initiated by intracellular superoxide. We then determined the effectiveness of MnCl2 as a superoxide scavenger in conscious horses by measuring the superoxide scavenging ability of equine plasma before and during intravenous infusions of 1.0 L volumes of 0.9% saline solution containing 0, 12.5, or 25 mM MnCl2. Plasma Mn concentrations, which were determined by atomic absorption spectrophotometry, increased as a function of time and dose. Intravenously administered MnCl2 concomitantly produced dose-related increases in superoxide scavenging ability of equine plasma at 15, 30, 45, and 60 minutes after the onset of infusion, compared with preinfusion control values. Heart rate and blood pressure of the treated horses, which were monitored to measure toxicity of MnCl2, gradually increased in both treatment groups. Clinical adverse effects of MnCl2 administration included defecation, pawing, hyperexcitability, flank watching, and sweating. The results of this study indicate that simple Mn salts may scavenge superoxide radicals in vivo with minimal adverse reactions and at a trivial cost.