Tear samples were collected from 1 eye of each of 40 cows, 27 sheep, 5 goats, and 5 human beings. Additionally, 10 bovine tear samples were pooled and concentrated. Spectrophotometric assays, using Micrococcus lysodeikticus, were performed on each sample to detect lysozyme activity expressed in hen egg lysozyme (HEL) equivalents. Lysozyme activity was not detected in tears of cows, but 158.8 +/- 159.3 mg of HEL/ml was detected in tears of sheep, 220.7 +/- 37.5 mg of HEL/ml in tears of goats, and 216.3 +/- 86.2 mg of HEL/ml in tears of human beings. In pooled bovine tear samples, lysozyme activity was not detected on plate assay and lysozyme protein was not detected on polyacrylamide gel electrophoresis, column chromatography, or immunoelectrophoresis with rabbit anti-bovine tear antibodies. On the basis of these observations, we concluded that the basic ocular protective mechanism in bovine tears is not lysozyme. Other antibacterial proteins such as lactoferrin, transferrin, complement, or beta-lysin may, therefore, be of primary importance in protecting the bovine eye.

Effects of topical administration of a single dose of 2% pilocarpine on intraocular pressure (IOP) and pupil diameter were evaluated in normotensive eyes of 10 clinically normal cats over 12 hours. Mean (+/- SEM) normal IOP was 17.1 (+/- 1.1) mm of Hg and, diurnal fluctuation was observed, with the highest IOP seen in the evening. Mean (+/- SEM) normal pupil diameter was found to be 10.1 (+/- 0.5) mm. Topical treatment with pilocarpine resulted in reduction of IOP in treated and nontreated eyes. This effect was time-dependent and was first observed at 4 hours after treatment. Mean reduction of IOP was 15.2% in the treated eye and 9.3% in the nontreated eye. The treated eye had reduced pupil diameter at 30 minutes after treatment, and miosis persisted throughout the 12 hours of the study. Mean reduction in pupil diameter was 28.5% in the treated eye and 14.2% in the nontreated eye. Topically administered pilocarpine results in reduction of IOP and pupil diameter in treated and contralateral eyes, which supports the use of pilocarpine for treatment of glaucoma in cats.

The vaccine efficacy of a genetically engineered deletion mutant strain of pseudorabies virus, strain 783, was compared with that of the conventionally attenuated Bartha strain. Strain 783 has deletions in the genes coding for glycoprotein I and thymidine kinase. In experiment 1, which had a 3-month interval between vaccination and challenge exposure, strain 783 protected pigs significantly (P < 0.05) better against virulent virus challenge exposure than did the Bartha strain. The growth of pigs vaccinated with strain 783 was not arrested, whereas that of pigs vaccinated with the Bartha strain was arrested for 7 days. Of 8 pigs given strain 783, 4 were fully protected against challenge exposure; none of the pigs given strain Bartha was fully protected. In experiment 2, which had a 3-week interval between vaccination and challenge exposure, the growth of pigs vaccinated with strain 783 was arrested for 3.5 days, whereas that of pigs vaccinated with the Bartha strain was arrested for 6 days. In experiment 3, pigs with moderate titer of maternal antibodies were vaccinated twice IM or once intranasally with either strain 783 or Bartha and were challenge-exposed 3 months after vaccination. Pigs given strain 783 twice IM were significantly (P < 0.05) better protected than were the other pigs. They had growth arrest of only 6 days, compared with 9 days for pigs of other groups, and shed less virus after challenge exposure. Results of this study indicate that the vaccine based on the deletion mutant strain 783 is more efficacious than is the Bartha strain of pseudorabies virus.

Total protein concentration was determined in serum, bronchoalveolar lavage (BAL) fluid, and nasal flush fluid obtained from specific-pathogen-free cats from birth to maturity and from adult conventionally raised cats. Protein components were analyzed by immunoelectrophoresis and isoelectric focusing. Albumin, and alpha, beta, and gamma-globulins were among the proteins identified in BAL fluid, and their isoelectric point ranged from 3.1 to 5.1. gamma-Globulin was not detected in serum or BAL fluid of newborn kittens before they had ingested colostrum. By day 3 after ingestion of colostrum, IgG was detected in high concentration in serum and was the predominant immunoglobulin in serum and BAL fluid of older cats. Nasal flush fluid from cats > 6 months old contained albumin, and alpha, beta, and gamma-globulins, with IgA being the predominant immunoglobulin. Total protein concentration in nasal flush fluid increased progressively with increasing age, and albumin was the predominant protein. Protein concentration was significantly (P < 0.01) higher in BAL fluid from conventionally raised adult cats than in that from specific-pathogen-free cats.

Bovine whey samples were evaluated by use of lymphocyte-transformation tests to determine their effect on lymphocyte blastogenesis. Whey samples from mammary glands with clinical mastitis strongly inhibited DNA synthesis and blastogenesis in lymphocytes stimulated with mitogens or dividing because of bovine leukemia virus infection. Whey samples from apparently healthy glands either did not inhibit lymphocyte DNA synthesis or inhibited it to a lesser degree than did whey from mastitic glands. Degree of inhibition was dose-dependent. The molecules causing inhibition were noncytotoxic and underwent minimal binding to the lymphocytes. Inhibitory molecules were susceptible to various proteolytic and glycolytic enzymes, indicating a glycoprotein-like structure. Whey inhibited incorporation of thymidine if it was in the cell cultures during the early stages of stimulation. Incubation of lymphocytes in whey that inhibited thymidine incorporation did not affect DNA synthesis in subsequent culturing of the same cells without whey. Degree of inhibition was affected by the method of whey preparation.

To determine the role of thromboxane A2 in the pathogenesis of experimentally induced immune complex glomerulonephritis, 12 concanavalin A-immunized Beagles were infused with 1 mg of concanavalin A via each renal artery and treated twice daily for 8 days with either 30 mg of CGS 12970/kg, PO, a specific thromboxane synthetase inhibitor, or placebo. The effect of treatment was assessed by measuring endogenous creatinine clearance and urine protein and eicosanoid excretion, and by evaluating changes in glomerular morphometric characteristics. On postinfusion day 8, urine protein, thromboxane B2, and 11-dehydro-thromboxane B2 excretion, glomerular epithelial crescent formation, and glomerular cell proliferation in the CGS 12970-treated dogs were significantly decreased when compared with values in the placebo-treated group. Differences were not observed in endogenous creatinine clearance, urine prostaglandin E2 and 6-keto-prostaglandin F1 alpha excretion, or glomerular polymorphonuclear leukocyte infiltration between groups in this study. These findings suggest thromboxane A2 has a role in the development of immune complex glomerulonephritis and that thromboxane synthetase inhibition may be beneficial in attenuating some of the functional and histologic changes associated with immune complex glomerulonephritis.

Tissues from cattle that died of experimentally induced mucosal disease (n = 3), naturally acquired mucosal disease (n = 6), or naturally acquired chronic bovine viral diarrhea (n = 4) were examined. Consistent findings were lymphocytic depletion of lymphoid tissues, degeneration of myenteric ganglion cells, and mild adrenalitis. Intracytoplasmic viral antigen was detected in myenteric ganglia and in endocrine glandular cells. Noncytopathic virus was isolated from all cattle, and cytopathic virus was isolated from 12 of 13 cattle.

Small intestinal explants from weaned pigs were cultured under a variety of conditions. Explants maintained villus-to-crypt ratio between 1:1 and 1.5:1 for 48 hours. The mucosal epithelium remained well preserved and retained good cellular morphologic features, as determined by light and electron microscopy. Between 48 and 72 hours, considerable mucosal degeneration was evident. Best results were obtained when the explants were cultured on a rocking platform placed in an atmosphere of 95% O2 and 5% CO2, using supplemented RPMI 1640 cell culture medium.

An ELISA was developed and tested for its ability to detect antibodies against Salmonella enteritidis in chickens. Various features of the ELISA were evaluated and optimized. The outer membrane protein antigens selected by use of the protein immunoblotting method made the assay specific and sensitive. The assay was evaluated in chickens experimentally infected with S enteritidis. Blood samples collected at weekly intervals after experimental infection with S enteritidis were analyzed by ELISA. Results of the ELISA were compared with those of conventional serum plate and microagglutination tests. The ELISA was more sensitive and specific in the detection of S enteritidis infection than the other 2 conventional tests.

Bone marrow fibroblast colony-forming units (CFU-F) were evaluated in cats experimentally infected with different isolates of FeLV. Cats infected with the Kawakami-Theilen isolate of FeLV (FeLV-KT) had progressive decrease in the number of CFU-F at 2, 4, and 6 weeks after infection. The number of CFU-F in FeLV-KT-infected cats ranged from 38 to 70% of the preinoculation CFU-F value. Of 3 cats with FeLV-KT-induced suppression of CFU-F, 2 developed fatal nonregenerative anemia. Cats infected with the Rickard isolate of FeLV (FeLV-R) had more moderate decrease in the number of CFU-F at 2, 4, and 6 weeks after infection. The number of CFU-F in FeLV-R-infected cats ranged from 62 to 82% of the preinoculation CFU-F value. The FeLV-R-infected cats did not become anemic.