The in vitro biologic effects of T-2 mycotoxin on the immune response of mice was undertaken. Twenty nanograms of toxin abrogated the immune response to the T-dependent antigen sheep RBC, whereas a partial response was observed when 2 ng was used. Analysis of cell culture viabilities indicated that cell death occurred with toxin doses that conincided with the diminished immune responses. A similar decreased response was observed against the T-independent antigen, TNP-lipopolysaccharide, indicating toxic effects on both B and T lymphocyte populations. Delay of toxin administration as much as 116 hours of the 120-hour incubation period still resulted in a substantially diminished immune response, indicating the toxin acts on both the afferent and efferent immune systems. Equal effects were observed for mice of the b, d, and k haplotype, indicating no apparent strain variability in sensitivity to T-2 mycotoxin effects. These results indicated that T-2 mycotoxin can modulate the immune response, and that this modulation is attributable to direct toxic effects on the cells of the immune system.

In a case-control study of risk factors associated with an episode of nosocomial Salmonella krefeld infection in dogs at the veterinary medical teaching hospital, data on 20 case dogs and 75 control dogs were obtained by review of hospital records. Univariate and multivariate statistical analyses were carried out for possible risk factors for infection to obtain odds of Salmonella krefeld isolation, given exposure to each risk factor of interest. Compared with control dogs, case dogs were 11.9 times more likely to have been fed rice, 7 times more likely to have had radiography done, 10.2 times more likely to have been a resident in ward 2, 5.6 times more likely to have been given antimicrobial agents orally, 11.3 times more likely to have been given antimicrobial agents parenterally, and 37.9 times more likely to have been given antimicrobial agents orally and parenterally (P less than 0.05).

Three antigens were prepared from Pasteurella multocida strain P-1059, and their immunogenicity and antigenic relationships were investigated. The 3 antigens were a soluble antigen purified from a 2.5% NaCl extract (2.5S), a similar antigen purified from an extract in 0.3% formalin solution containing 0.85% NaCl (FS), and lipopolysaccharide (LPS). The antigens were treated with various chemicals and enzymes to study their antigenic and immunogenic determinants. Antigenic analyses with ELISA inhibition tests indicated that 2.5S and FS were similar LPS-protein complex antigens. The 2.5S and FS antigens induced protective immunity in turkeys with high antibody titers against LPS antigen. Although LPS was a component of 2.5S and FS,LPS itself was poorly immunogenic in turkeys. The antigenicity of protein compounds in 2.5S was deteriorated by protease treatment, which, however, did not significantly diminish the protective immunogenicity. Treatment of 2.5S with sodium periodate, altering its carbohydrate moieties, decreased its immunogenicity. The immunogenicity of 2.5S also was abolished by phenol-water treatment, owing to dissociation of the LPS-protein complex. These findings suggest that a certain form of LPS-protein complex is essential for the induction of immunity against the P multocida infection in turkeys.

The patency of mammary papillae was reestablished after surgically induced injury. Perforated prosthetic tubes with affixed Dacron tubing or Teflon strips were implanted in 18 abrabed papillae of lactating dairy cows and were secured with sutures. Wound healing was assessed by palpation and visual inspection. All wounds, with one exception, healed by first intention. Machine milking, reinstituted on day 5 after surgery, caused no apparent discomfort. Grossly and histopathologically, all implants stimulated a variable degree of mucosal metaplasia and hyperplasia. Only implants with Teflon strips became anchored by fibrotic invasion. Mastitis, tube migration, and milk fistulas were complications of the procedure.

A percutaneous biopsy technique for the study of endochondral bone formation in the dog was developed. With the dogs under general anesthesia or sedated with a combination of a tranquilizer and a local anesthetic, biopsy specimens were obtained from the proximal growth plate of the humerus with the use of a Jamshidi bone biopsy needle. Biopsy specimens were structurally intact, and contained epiphysis, growth plate, and metaphysis. The procedure proved to be a simple, safe technique, which caused minimal discomfort for the patient and did not affect the growth of the proximal end of the humerus, even after multiple biopsies.

In an attempt to isolate monoclonal antibodies specific for bovine lymphocytes, spleen cells from mice immunized with bovine lymphocytes were fused with the mouse myeloma cell line SP-2/0. The resulting hybridoma cell lines were tested for reactivity with bovine lymphocytes, polymorphonuclear neutrophils, RBC, gamma-globulin, kappa-casein, beta-casein, alpha-S1-casein, and beta2-microglobulin (beta2m) and with beta2m from rabbits, goats, and human beings. None of the clones secreted anti-bovine lymphocyte-specific antibody. However, 4 secreted monoclonal antibodies to bovine beta2m. They also reacted with beta2m from rabbit, goat, and human being. One monoclonal antibody also was found to be reactive with bovine immunoglobulin. Monoclonal antibodies to beta2m could serve as a tool to (1) exlore the homology of the beta2m molecule among various species, (2) examine the relationship of beta2m with the constant region of the immunoglobulin molecule, (3) quantitate bovine beta2m in various body fluids and major histocompatibility antigens on cell surfaces, (4) help characterize those antigens in cattle, and (5) be used for tissue typing of those antigens.

Primigravid swine were vaccinated orally with a live enterotoxigenic Escherichia coli (ETEC) strain that produces pilus antigen K99. The titers of K99 antibody in colostrum and milk of vaccinates remained higher than those of nonvaccinated controls through the first lactation after vaccination (4 weeks). Some control swine had low titers of K99 antibody in colostrum or developed low titers of K99 antibody in milk during lactation. Lacteal K99 antibody titers of vaccinates dropped to control levels during the second lactation, 6 months after vaccination. Pigs suckling vaccinates and controls were equally susceptible to challenge exposure to K99+ ETEC during the second lactation. Orally vaccinated swine given a parenteral booster vaccination (with killed K99+ ETEC) during their second gestation had K99 antibody in milk through their second lactation. During the second lactation, these orally vaccinated parenterally revaccinated swine had higher titers of K99 antibody in postcolostral milk than did nonvaccinated controls, controls given only the parenteral booster injection, or controls vaccinated parenterally during both gestations.

During the 1986 lambing season, 33 Michigan sheep producers submitted all lambs that had died before weaning to the Michigan State University Diagnostic Laboratory for necropsy. Inductively coupled argon plasma emission spectroscopy was used to measure 22 elements in the liver of 888 of the lambs submitted. Mean concentrations of each element were established and compared with literature values of established deficient, normal, and toxic concentrations. Mean values in milligrams per kilogram of wet weight were as follows: A1, 3.843; As, less than 1; Ba, 0.176; Ca, 128.2; Cr, 0.778; Cu, 56.82; Fe, 491.6; Hg, less than 2; K, 2,150; Mg, 138.4; Mn, 2.776; Mo, 0.489; Na, 1,384; P, 2,583; Pb, 1,453; Sb, less than 1; Tl, less than 5; Zn, 68.31. In only 11 lambs did the liver contain As, B, Cd, Co, Hg, Sb, Se, or Tl in detectable concentrations.

Autologous canine neutrophils were labeled with technetium 99m and reinjected in 7 dogs with experimentally induced focal abscessess to determine the ability of scintigraphy to localize a focus of sepsis (abscess). Good localization of labeled cells in an abscess was achieved; however, a large portion of the technetium 99m eluted from the neutrophils.

Experiments concerned with the immunogenicity, pathogenicity, and transmissibility of a recombinant vaccinia:Sindbis virus were conducted. The WR strain of the recombinant vaccinia:Sindbis virus was found to be infective for calves and mildly pathogenic, resulting in local tissue reaction. It was not transmissible to other calves. Also, it was found to be immunogenic when inoculated intradermally into calves, and antibody was produced against the parent vector virus (vaccinia) and the Sindbis antigen. Recombinant virus given IV to calves induced no detectable clinical signs, nor did the calves develop neutralizing antibodies. Furthermore, second-passage lesion material containing up to 10(7) tissue culture infective doses of the recombinant virus failed to induce development of lesions or illness in intradermally inoculated calves, and virus could not be recovered from the inoculation sites. In this series of experiments, this vaccinia recombinant given intradermally was immunogenic, mildly pathogenic at the local injection site only, and was not transmissible to contact animals, thus demonstrating the potential efficacy and safety of the WR strain of vaccinia virus when used as a live vector system in cattle.