Oral treatment of transmissible gastroenteritis with natural human interferon alpha: a field study.

During a natural outbreak of transmissible gastroenteritis (TGE), groups of piglets were treated orally for 4 consecutive days with placebo or 1.0, 10.0 or 20.0 international units (IU) natural human interferon alpha (nHuIFN alpha). Piglets that were 1-12 days of age and given 1.0, 10.0 or 20.0 IU nHuIFN alpha had significantly (P < 0.01) greater survival rates than placebo-treated piglets; survival rates were the greater for the highest level of nHuIFN alpha treatment. In contrast, beneficial effects of nHuIFN alpha were not observed in piglets farrowed during the disease outbreak and given nHuIFN alpha within hours of birth. Oral nHuIFN alpha therapy modulates the natural course of high morbidity and mortality commonly seen with TGE.

Serum copper, zinc, calcium and phosphorus concentrations of calves stressed by bovine respiratory disease and infectious bovine rhinotracheitis.

The relationship between serum minerals and stress and(or) disease has not been fully evaluated in beef cattle. Two trials were conducted to determine the changes in serum Cu and Zn during market-transit stress and(or) disease. Two additional trials were conducted to determine the changes in serum Cu and Zn after inoculation with infectious bovine rhinotracheitis virus (IBRV), with one of the trials determining the changes in serum Ca and P. Trials 1 (n = 80) and 2 (n = 100) utilized calves that were handled through a normal market-transit system and transported 1,967 km to the feedlot. Trials 3 (n = 37) and 4 (n = 8) used calves that were sero-negative to IBRV and then challenged with 2.7 x 10(5) plaque-forming units of the virus. Serum samples were collected at specified intervals and serum minerals were measured for each trial. Serum Zn for morbid or IBRV-challenged calves was decreased by 34, 57, 29 and 15% (P less than .05) for the four trials, respectively, at peak morbidity. Serum Cu of morbid or IBRV-challenged calves increased 5, 15, 40 and 33% for the four trials, respectively, at peak morbidity. Feed intakes were lower during morbidity for market-transit trials and after IBRV inoculation. Lower feed intake could partially explain the decrease in serum Zn; however, when feed intake was held constant, serum Zn concentration still decreased. Serum Zn decreased and serum Cu increased during market-transit morbidity or after IBRV.

Transfer of interferon alfa into human breast milk.

Originally assumed to be antiviral substances, the efficacy of interferons in a number of pathologies, including malignancies, multiple sclerosis, and other immune syndromes, is increasingly recognized. This study provides data on the transfer of interferon alfa (2B) into human milk of a patient receiving massive intravenous doses for the treatment of malignant melanoma. Following an intravenous dose of 30 million IU, the amount of interferon transferred into human milk was only slightly elevated (1551 IU/mL) when compared to control milk (1249 IU/mL). These data suggest that even following enormous doses, interferon is probably too large in molecular weight to transfer into human milk in clinically relevant amounts.

Isolation and characterization of encephalitic bovine herpesvirus type 1 isolates from cattle in North America.

Nine CNS bovine herpesvirus type 1 (BHV-1) isolates, recovered from bovine brain samples submitted to the Texas Veterinary Medical Diagnostic Laboratories from 1974-1989, were compared by analyzing their DNA restriction endonuclease (RE) fragment migration pattern. Seven had pattern similar to that of the respiratory BHV-1 Cooper strain. The remaining 2 isolates, however, had variant patterns, similar to that of each other, but completely different from patients for the other 7. The RE patterns of these 2 variants were similar to published RE patterns for 2 encephalitic or neuropathogenic BHV-1 strains--the Australian N-569 strain and the Argentine A-663 strain. One of the Texas encephalitic variants (No. 30326) was isolated from the CNS of a calf that died during an epizootic of encephalitis in 1974. The other, designated TX-89, was isolated in 1989 from the CNS of a 7-month-old feedlot steer with acute fatal encephalitis. Microscopic lesions of encephalitis with neuronal degeneration and intranuclear inclusions were observed for 3 of the 9 isolates, the 2 variant isolates (No. 30326 and TX-89), and a respiratory isolate. The remaining 6 CNS isolates, all respiratory subtypes, were recovered from cattle that did not have clinical CNS disease or gross or microscopic CNS lesions; in 5 of these cattle, virus was recovered from at least 1 other organ (lungs) besides the CNS. We conclude that the CNS of calves can be naturally infected with 2 distinct BHV-1 subtypes, the respiratory and the encephalitic, and that the encephalitic subtype (subtype 3 or BHV-1.3) has been present in Texas cattle since at least 1974.

Horizontal transmission of pseudorabies virus in cattle.

Pseudorabies virus (PRV) was not transmitted horizontally from 3 PRV-infected calves to 2 contact control calves during 4 days of comingling in experiment 1. Although these contact control calves developed clinical signs of pseudorabies when infected intranasally with PRV in experiment 2, they did not transmit PRV to a second pair of contact control calves. However, 1 of 2 pigs comingled with these 4 calves seroconverted. During both experiments, moderate amounts (10(2) to 10(5) TCID50) of PRV were present in the nasal secretions of the infected calves during the contact periods. All infected calves traumatized their nares or periorbital tissue. Infected calves developed a nonsuppurative meningoencephalitis mainly involving the brain stem. Four of the 5 infected calves had nonsuppurative ganglioneuritis and acute lymphoid necrosis of germinal centers. Virus could not be recovered from nasal and tonsillar swab samples from contact-control calves and pigs.

Vaccination of pregnant ponies against equine rhinopneumonitis.

Bovine herpesvirus 1247 (one dose) was given subcutaneously to five pregnant pony mares between 227 and 319 days of their gestations. There were no adverse clinical reactions, and the virus was not recovered from nasal swabs collected during a 2-week period after vaccination. Four ponies foaled full-term, live, healthy foals. The foal of the fifth mare (No. 1) was found dead, but on the basis of the pathologic and virologic examinations, the virus was not considered to be the cause of the death. At 3 weeks after vaccination, the pregnant pony mares had a 13- to 250-fold increase in serum antibody titer to equine herpesvirus-1. A virulent-virus challenge exposure of all pony mares at 208 days after vaccination resulted in antibody titers greater than those just before this exposure. Virus was recovered from nasal swabs from vaccinated mares only on postexposure day 1, whereas the one control (nonvaccinated) pony shed virus for at least 3 days after challenge exposure. The immunogenic and the nonabortifacient characteristics of the herpesvirus 1247 in pregnant pony mares indicate that it may be useful to vaccinate horses against equine herpesvirus-1.

Immunoassay for the steroid-induced isoenzyme of alkaline phosphatase in the dog.

Antiserum directed against the steroid-induced alkaline phosphatase (ALP) isoenzyme of the dog was produced in rabbits. This antiserum was used to develop a sensitive and quantitative assay for the detection of the steroid-induced ALP isoenzyme in the serum of dogs. This antiserum was also used to enhance the electrophoretic separation of the steroid-induced and hepatic ALP isoenzymes.

Comparison of the steroid-induced, intestinal, and hepatic isoenzymes of alkaline phosphatase in the dog.

The steroid-induced, intestinal, and hepatic isoenzymes of canine alkaline phosphatase (ALP) were compared, using antibodies against the steroid-induced ALP isoenzyme, heat inactivation, phenylalanine inhibition, prednisolone inhibition, and Michaelis constant determinations. The results indicate that the steroid-induced and intestinal ALP isoenzymes are similar and indicate that the steroid-induced isoenzyme might be a product of the same gene that controls the intestinal isoenzyme.

Development of pneumonia in desert bighorn sheep after exposure to a flock of exotic wild and domestic sheep.

From 1986 to 1989, 5 desert bighorn sheep (3 Ovis canadensis mexicana and 2 O c nelsoni), ranging in age from 2 to 3 years, were exposed to a flock of exotic wild and domestic sheep to potentially achieve naturally acquired pneumonia. Pasteurella multocida was isolated from nasal samples from 4 of 6 sheep randomly sampled from the flock. Bighorn sheep were exposed individually and each exposure period was a trial. Treatment before and after exposure varied and included combinations of alpha interferon, antibiotics, anti-inflammatory drugs, and vaccines. Treatments were chosen on the basis of recommendations of others for treating pneumonia in desert bighorn sheep as well as our own experience in sheep and cattle. Regardless of treatment used, bighorn sheep in trials 1 to 4 developed signs of pneumonia within 10 to 14 days of exposure. Bighorn sheep in trials 1 to 3 died within 11 to 17 days of initial exposure. In trial 4, the bighorn sheep was isolated from the carrier sheep for treatment of pneumonia on day 14 and died on day 30. Pasteurella multocida was isolated from lung tissue in 3 of the 4 bighorn sheep. On the basis of results of trials 1 to 4, a more in depth clinical study was conducted in trial 5. Nasal and blood specimens were collected prior to and during trial 5 for bacteriologic culturing and serologic testing for bovine viral diarrhea virus, infectious bovine rhinotracheitis, parainfluenza-3 virus, and respiratory syncytial virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoglobulins produced by the antigenized equine fetus.

The foal is born without detectable antibody and except for small amounts of IgM is devoid of immunoglobulins. Intrafetal administration of either Venezuelan equine encephalomyelitis virus (VEE-TC83) or ovine erythrocytes elicited IgGa, IgGb and a trace of IgG(T). The fetal blood VEE-TC83 neutralization titre was higher than the neutralization titre elicited by the same preparation in older horses.

Induced latency in pseudorabies vaccinated pigs.

A latent pseudorabies virus infection was established in pigs despite vaccination with a modified-live pseudorabies virus vaccine. Although the vaccinated pigs developed high concentrations of antibody, virus was recovered from the tonsils and lungs of pigs treated with dexamethasone three months after inoculation with virulent virus. These results may explain why vaccination programs have failed to eliminate the persistence and spread of virulent pseudorabies virus in infected herds.

Antibody responses by cattle after vaccination with commercial viral vaccines containing bovine herpesvirus-1, bovine viral diarrhea virus, parainfluenza-3 virus, and bovine respiratory syncytial virus immunogens and subsequent revaccination at day 140.

Calves were vaccinated with four different commercial viral vaccines containing bovine herpesvirus-1 (BHV-1), bovine viral diarrhea (BVDV), parainfluenza-3 virus (PI-3V), and bovine respiratory syncytial virus (BRSV) immunogens. For the initial vaccination certain vaccines were given twice (days 0 and 28), whereas other vaccines were given on day 0. The calves received another injection on day 140 with the vaccine originally given on day 0. The sera were collected at days 0, 7, 14, 21, 28, 42, 56, 84, 112, 140, 154, 168, and 196 and assayed for viral neutralizing antibodies. The calves were seronegative to BHV-1, BVDV, and BRSV at the onset of the experiment; however, the calves were PI-3V antibody positive due to prior active infection. The commercial vaccines were: (I) inactivated; (II) modified live virus (MLV); (III) combination of chemically altered live virus, MLV, and inactivated virus; and (IV) combination of inactivated and MLV. Among the vaccine groups there were differences in onset and duration of antibodies as measured by geometric mean titers to each immunogen in postvaccination collection dates compared to day 0 titers; and likewise compared to day 140 titers after revaccination at day 140. There were also differences in antibody titers to the various viruses among the vaccine groups on specific collection dates. All four vaccines induced increased BHV-1 antibodies by day 14 after the initial injection. The antibody titers induced by MLV BHV-1 and the chemically altered BHV-1 vaccines had greater duration than those induced by the inactivated vaccine.(ABSTRACT TRUNCATED AT 250 WORDS)