Inbreeding and canine mammary cancer: a retrospective study.

Using files of the Animal Neoplasm Registry (ANR) in Alameda and Contra Costa Counties, California, we conducted a retrospective study to compare the degree of inbreeding in the ancestry of purebred dogs with mammary and other cancers, and of those without tumors. Wright's coefficients of inbreeding, calculated for all animals in the three groups, ranged from 0.000 to 0.535. The median inbreeding coefficients of the mammary cancer and comparison groups (consisting of other cancers) were approximately twice that of the nonneoplastic group, but neither difference was statistically significant. Dogs with mammary adenocarcinoma and mixed mammary cancer had similar degrees of inbreeding.

Quantitative light microscopic localization of [3H]naltrindole binding sites in the rat brain.

The binding of radiolabeled naltrindole ([3H]NTI), a selective delta-opioid antagonist, was characterized using receptor autoradiography. Receptor binding properties were established in brain paste slices which demonstrated one site receptor occupancy with an apparent Kd of 0.25 +/- 0.08 nM (Bmax of 597.5 fmol/mg protein). Autoradiographic localization of [3H]NTI binding sites in the rat brain revealed high densities of these sites in the cortex (layers 1-3 and 6), caudate putamen, accumbens, claustrum, and internal plexiform layer of the olfactory bulb. Moderate to low levels of specific binding were observed in the hippocampus, thalamus, and substantia gelatinosa of the spinal cord.

DNA probe for detection of serogroup O157 enterohemorrhagic Escherichia coli.

To develop a probe for the detection of serogroup O157 enterohemorrhagic Escherichia coli (EHEC), plasmid DNA extracts from 16 E. coli strains that hybridized with the CVD419 probe were screened for restriction fragments present in plasmids of serogroup O157 E. coli strains, but not in plasmids of non-O157 E. coli strains. Using a single O157:H7 E. coli strain (639I), 10 serogroup O157 E. coli specific fragments were then removed, radiolabeled and hybridized (42 degrees C) with colony blots of both groups of strains. A 2.0 kb SmaI fragment probe (VPM1) was the most specific for serogroup O157 EHEC. Using a larger set of 41 non-E. coli and 107 E. coli strains from human, animal and meat sources, VPM1 hybridized with all 49 serogroup O157 EHEC strains. None of 8 enterotoxigenic E. coli (ETEC), including serogroup O157 strains, nor any of the 41 non-E. coli with the VPM1 probe. However, this probe hybridized with 5 of 50 non-O157 E. coli which were verotoxin (VT) or CVD419 probe-positive. Increased hybridization stringency (45 degrees C) reduced the 5 false-positives to 2 negatives and 3 trace responses, which were easily distinguishable from positive responses.

Characteristics of Vero cytotoxin producing Escherichia coli associated with intestinal colonization and diarrhea in calves.

Isolates of Escherichia coli which produce Vero cytotoxin (VTEC) were obtained during 1983-1989 from calves raised in 5 north-central states of the USA. All of the calves experienced intestinal epithelial colonization by VTEC, diarrhea or both; twelve of the calves had bloody diarrhea. Twenty one isolates were serogroup O111 and the others were O103, O69, O45, 026, O5, or non-typable (4 isolates). All but one of the isolates hybridized with the CVD419 probe which identifies most VTEC strains. Thirty two isolates hybridized with the VT1 probe, 3 with both the VT1 and VT2 probes, and one with neither probe. The culture filtrate of the VT probe negative isolate was partially neutralized by SLT I monoclonal antibody. For the other isolates, the results of toxin neutralization by anti-SLT I and anti-SLT II monoclonal antibodies corresponded exactly with the VT1 and VT2 probe hybridization results. Three of the strains adhered in a localized manner to HEp-2 cells and Intestine 407 cells.

Acute lead poisoning with eosinophilic meningoencephalitis in calves on a farm receiving land application of sewage sludge.

A total of 3 cases of acute lead poisoning in calves was confirmed by atomic absorption spectrophotometric analysis of biological samples, presence of an acute lead exposure source, clinical signs of impaired vision in one case and eosinophilic meningoencephalitis in another case. One of two other calves which died approximately 2 months earlier had nervous signs and it is likely that they also had lead poisoning. Dams of two of the cases did not have elevated lead levels. Municipal sewage sludge had been applied to most fields on the farm during the preceding 5 year period. There had been approximately a doubling of the lead content in the soil; however, the foodstuffs produced on the farm had low lead concentrations. The extremely high lead levels in the abomasal contents and feces of calves eliminated sludge as the source of the lead in this acute poisoning episode. The contents of oil filters, accessible to calves but not to adult cattle, had lead levels as high as 26,922 micrograms/g and was the most likely lead source responsible for this lead intoxication. It appears that the manifestation of eosinophilic meningoencephalitis in lead poisoning cases may occur in young calves as well as in cows and in acute as well as in chronic intoxications.

Plasmid analysis and epidemiology of Salmonella enteritidis infection in three commercial layer flocks.

Ninety-six S. enteritidis isolates obtained from three commercial layer flocks in 1988-90 were examined following DNA extraction, restriction enzyme digestion, and gel electrophoresis for plasmid size profiles and restriction fragment length polymorphisms (RFLPs). The S. enteritidis isolates from the three flocks had three, eight, and two different plasmid profiles, respectively. Only four isolates from one flock lacked plasmids. A 36-megadalton (mDa) (54-kilobase) plasmid was present in 73% of the isolates, either alone or in combination with other plasmids. Isolates with only the 36-mDa plasmid had identical RFLPs. The diversity of plasmid profiles was greater than that of phage-types among isolates from the three flocks: 12 unique plasmid profiles vs. four phage-types. Mixed infections with S. enteritidis strains having distinct plasmid profiles occurred in all three flocks. Reinfection of these flocks in 1990 with one or more of the strains obtained earlier was evident, because some of the original isolates and the 1990 isolates had matching plasmid profiles and were of the same phage-types. Isolates from both environmental and tissue samples, examined from one flock, were found to share the same plasmid profile and phage-type.

Quantitative index for diagnostic surveillance of neoplasms in dogs.

The probability of detecting a neoplasm in dogs with a previous or concurrent tumor may not be the same as the probability of observing a first neoplasm in the general canine population. A population-based index was developed to quantitate the diagnostic surveillance of tumor-bearing and nontumor-bearing dogs. The index was derived from each dog's excess submissions defined as the difference between the number of tissues submitted for microscopic examination during a dog's registration and the number of confirmed neoplasms derived from the submissions. Based on this index, 14.2% of additional tumors diagnosed in dogs already bearing at least one tumor could be attributed to a difference in the excess submission measure of diagnostic surveillance. This difference in diagnostic surveillance was constant over breed, sex, and tumor type.

Serologic enzyme-linked immunosorbent assay responses of calves vaccinated with a killed Mycobacterium paratuberculosis vaccine.

The purpose of this study was to document the effect of calfhood vaccination for Mycobacterium paratuberculosis on a serologic ELISA. Fifteen calves vaccinated with a killed paratuberculosis vaccine and 5 unvaccinated control calves were tested from the first through the fifteenth month of life. Age of vaccination ranged from 5 to 40 days. Blood samples were collected prior to vaccination and periodically thereafter. Serum antibody was analyzed by use of the ELISA. All calves were ELISA-negative prior to vaccination. Thirteen of 15 vaccinated calves became ELISA-positive between 2 and 6 months after vaccination. The unvaccinated cohort remained ELISA-negative. Wide-spread use of vaccine may interfere with diagnosis of paratuberculosis and with control programs that are based on serologic tests that measure humoral antibody.

Characterization of Mycobacterium paratuberculosis antigenic proteins.

The characterization of a purified antigen from Mycobacterium paratuberculosis, recently made commercially available for use in serodiagnosis by enzyme-linked immunosorbent assay (ELISA), of paratuberculosis in cattle was described. This assay had 89% specificity and 83% sensitivity for M paratuberculosis infection. The protein/polypeptide composition of the purified antigen was compared with that of a crude protoplasmic extract of strain 18 M paratuberculosis used in the agar-gel immunodiffusion test and ELISA and with that of sonicated strain 19698 M paratuberculosis organisms grown on Dorset-Henley synthetic liquid medium. The sonicated M paratuberculosis contained 27 major proteins/polypeptides; the crude protoplasmic extract, 18; and the purified antigen contained 14 proteins/polypeptides, using sodium dodecyl-sulfate polyacrylamide-gel electrophoresis analysis. The serologic reactivity of these proteins/polypeptides were defined, using the enzyme-linked immuno-electrotransfer blot technique. The sonicated M paratuberculosis contained 20 serologically reactive proteins/polypeptides (34,000 to 84,000 daltons); the crude protoplasmic extract contained 3 (37,000 to 45,000 daltons); and the purified extract contained a diffuse polypeptide band (34,000 to 38,000 daltons). Identification by enzyme-linked immuno-electrotransfer blot technique of M paratuberculosis antigens reactive in the ELISA will allow us to further study these antigens in the ELISA to improve sensitivity and specificity of the diagnostic test.

Comparison of antibodies to Leptospira in white-tailed deer (Odocoileus virginianus) and cattle in Ohio.

A survey was conducted to determine the prevalence of leptospiral antibodies in sera from 248 white-tailed deer (Odocoileus virginianus) in Ohio. The sera were collected at check stations during the hunting season in 1983. The microscopic agglutination microtiter test was used to determine the presence of antibodies to Leptospira interrogans serovars pomona, icterohemorrhagiae, canicola, hardjo, and grippotyphosa. Eighteen of 248 (7.3%) serum samples had antibody titers (greater than or equal to 1:100) to at least one of the five serovars tested, with three of these samples reacting to more than one serovar. Prevalence did not differ significantly between sex or age groups. The serovar antigens reacting most frequently with serum antibodies were grippotyphosa (10 of 22, 45.5%) and pomona (eight of 22, 36.4%). Sera agglutinating with pomona antigen had higher titers (ranging from 1:200 to 1:6,400) than did sera agglutinating with the other serovars. These results were compared to results obtained from cattle tested at the Ohio Department of Agriculture Laboratories during 1983. There was a significant relationship between pomona infections detected in deer and cattle (P less than 0.05), but not with grippotyphosa.