Refine search
Results 1-10 of 35
Characteristics and application of monoclonal antibody to progesterone, 2; Development of progesterone enzyme-linked immunosorbent assay (ELISA).
1991
Kang C.B. | Kim J.S.
Cross protection among Haemophilus parasuis strains in immunized gnotobiotic pigs
1991
Miniats, O.P. | Smart, N.L. | Rosendal, S.
In an attempt to establish if cross protection can be induced by different strains of Haemophilus parasuis, three groups of 12 gnotobiotic pigs were immunized each with an aluminum hydroxide adsorbed whole cell bacterin of one of three H. parasuis strains. Two weeks later, four pigs within each vaccinated group were challenged with aerosols of live cultures of each of the three test strains and observed for response. Two virulent strains V1 and V2 protected all the vaccinated pigs, while all non-vaccinated controls succumbed to Glasser's disease when challenged with these strains. Vaccination with strain LV (of low virulence) protected the pigs against challenge with strain V2, but not against strain V1. Strain LV did not cause disease in the immunized animals and only in one of ten nonimmunized pigs upon second challenge. The results suggest that strains may differ in antigenicity and that virulence and immunoprotection are positively related. Strains to be used in commercial vaccines should therefore be selected carefully. Antibodies detected in the sera of vaccinated pigs were to outer membrane proteins of the bacteria, but not to lipopolysaccharides or capsular polysaccharides. This would suggest that for gnotobiotic pigs outer membrane proteins are more immunogenic than lipopolysaccharide or capsular antigens. Further work is needed to determine if outer membrane proteins also contribute protective immunogens.
Show more [+] Less [-]Mucosal and systemic antibody responses to bovine coronavirus structural proteins in experimentally challenge-exposed calves fed low or high amounts of colostral antibodies
1991
Heckert, R.A. | Saif, L.J. | Mengel, J.P. | Myers, G.W.
Ten colostrum-deprived calves were assigned to 1 of 2 treatment groups (5 calves/group), and fed colostrum that had either low (naturally infected cows) or high (immunized cows) antibody titers to bovine coronavirus (BCV). All calves were inoculated orally and intranasally with virulent BCV when they were 24 to 48 hours old and challenge exposed 21 days later. Blood, feces, nasal secretions, tears, saliva, and bronchoalveolar lavage (BAL) fluids were collected weekly from each calf for 5 weeks after inoculation. The titers to whole BCV or the relative amounts of isotype-specific antibodies to BCV structural proteins were evaluated in these samples by ELISA or immunoblotting, respectively. Both pools of colostrum contained primarily IgG1, IgG2, and IgA antibodies to the E2 and E3 BCV proteins. Calves fed the high-titer colostrum had correspondingly higher amounts of passive IgG1 and IgA antibodies to whole BCV and to the E2 and E3 BCV proteins in serum, feces, and BAL fluid at postinoculation week 1 than those calves fed low-titer colostrum. Active IgG1, IgA and IgM antibody responses in serum and active IgA and IgM antibody responses in most mucosal secretions to whole BCV and to the E2 and E3 proteins were lower or delayed in calves fed high-titer colostrum, compared with responses in calves fed low-titer colostrum. In contrast, increased responses to the BCV N protein were observed in all samples (except in serum and BAL fluid) in the calves fed high-titer colostrum, compared with calves fed low-titer colostrum. Upon challenge exposure, responses to E2 and E3 BCV proteins in serum and BAL fluid were lower in the group fed high-titer colostrum, compared with those in the group fed low-titer colostrum. Our findings indicate that the level of passive immunity in calves at the time of BCV inoculation can influence the development of active antibody responses in serum, feces, and mucosal secretions to whole BCV and to some BCV proteins individually.
Show more [+] Less [-]Immunocytochemical study of tissues from clinically normal dogs and of neoplasms, using keratin monoclonal antibodies
1991
Sandusky, G.E. | Wightman, K.A. | Carlton, W.W.
Three commonly used keratin monoclonal antibodies (MAB)--AE1:AE3, CAM 5.2, and MAK-6--were compared with routinely used cytokeratin antibody. The expression of these antibodies was analyzed in several tissues obtained from clinically normal dogs and in a variety of neoplasms from dogs. Using appropriate enzymatic digestion, paraffin-embedded tissues processed in routine manner retained their typical keratin expression. Differentiated and poorly differentiated epithelial neoplasms, lymphomas, and melanomas were studied by use of the avidinbiotin-peroxidase technique. All 4 of the aforementioned antibodies had similar staining profiles. Of 3 anaplastic carcinomas, 2 had positive reaction to all 4 antibodies. All lymphomas, plasma cell tumors, and amelanotic melanomas had negative reaction to MAK-6, CAM 5.2, AE1:AE3, and cytokeratin MAB. Three basal cell epitheliomas had positive reaction to all 4 antibodies, whereas 1 basal cell tumor with a solid pattern had negative staining reaction. Two carcinoids had negative reaction to all markers and 1 of 2 malignant chemodectomas and 1 transitional cell carcinoma had staining reaction to only AE1:AE3 MAB. Comparing the 4 antibodies, use of AE1:AE3 MAB produced the strongest staining intensity followed by cytokeratin, MAK-6, and CAM 5.2 MAB. All 4 antibodies had low background staining. In conclusion, AE1:AE3 and MAK-6 MAB are as useful as cytokeratin MAB for identification of poorly differentiated epithelial neoplasms in dogs and cats.
Show more [+] Less [-]Eosinophilic myositis in Canadian cattle
1991
Smith, H.J. | Snowdon, K.E. | Finley, G.G.
Musculature from 198 Canadian cattle with suspected lesions of eosinophilic myositis were examined histologically and by pepsin digestion. Sera from 51 of the 198 animals were also examined by enzyme-linked immunosorbent assay (ELISA) for anti-Trichinella antibodies. Viable larvae of Trichinella were not recovered from any of the cattle but one animal from Ontario tested positive for anti-Trichinella antibodies. Histologically, focal and/or diffuse eosinophilic myositis lesions were observed in 149 (75.2%) of the animals studied. Other conditions identified were sarcocystiosis, abscesses, cysticercosis, steatosis, fibrosis, granuloma, lymphosarcoma and necrosis. Sarcocystiosis was identified in 105 of the 198 animals in both normal and affected musculature. The study indicates that trichinosis is not a primary cause of eosinophilic myositis in cattle.
Show more [+] Less [-]Prospective vaccine prepared from a new mutant of Toxoplasma gondii for use in cats
1991
Frenkel, J.K. | Pfefferkorn, E.R. | Smith, D.D. | Fishback, J.L.
Kittens are the principal disseminators of Toxoplasma gondii. They can shed > 10(8) oocysts in the feces after initial infection with bradyzoites in tissue cysts. Thereafter, most kittens develop protective immunity and do not shed oocysts again if they are reinfected. Bradyzoites of a T gondii mutant, designated T-263, were used to vaccinate kittens. Their use did not result in oocyst shedding, but successfully prevented 84% (31/37) of the kittens from shedding oocysts when challenge exposed with a normal isolate of T gondii. Vaccination of outdoor-roaming cats and kittens would be a useful public health measure to prevent transmission of toxoplasmosis near homes, on farms, and in zoos. It is anticipated that several years will be required for a lyophilized bradyzoite vaccine to be ready for licensing and possible commercial availability.
Show more [+] Less [-]Detection of anti-equine neutrophil antibody by use of flow cytometry
1991
Jain, N.C. | Stott, J.L. | Vegad, J.L. | Dhawedkar, R.G.
Flow cytometric and conventional fluorescence microscopic methods were compared to detect heterologous (rabbit) neutrophil antibody bound to equine neutrophils. Unfixed and paraformaldehyde-fixed neutrophils were treated with normal rabbit serum or various dilutions of an antineutrophil serum. The cells were then reacted with fluorescein conjugates of goat anti-rabbit IgG, staphylococcal protein A, and streptococcal protein G. Antibody binding was evaluated by use of fluorescence microscopy and flow cytometry. Unfixed neutrophils treated with normal rabbit serum did not fluoresce, whereas many of the fixed neutrophils had distinct cytoplasmic and some membranous (nonspecific) fluorescence. Unfixed cells treated with the antiserum had localized areas (capping) of intense membrane fluorescence, whereas fixed cells had bright uniform membranous fluorescence. The intensity of specific fluorescence varied with the antiserum dilution and the conjugate. On flow cytometry, over 80% of unfixed cells treated with antiserum dilutions up to 1:1,024, 1:2,048, and 1:256 fluoresced, respectively, with anti-IgG, protein-G, and protein-A conjugates. Fixed cells generally had similar percentages of fluorescent cells, but at a higher (1-step) antiserum dilution. It was concluded that flow cytometry is more sensitive than conventional fluorescence microscopy to detect antibodies associated with equine neutrophils.
Show more [+] Less [-]Determination of ability of a thymidine kinase-negative deletion mutant of bovine herpesvirus-1 to cause abortion in cattle
1991
Jones, Ever | Whetstone, C.A. | Bello, L.J. | Lawrence, W.C.
The Cooper isolate of bovine herpesvirus-1, which causes abortion in cattle, was used to construct a thymidine kinase-negative (TK-) deletion mutant virus. Twelve heifers were inoculated IV at 25 to 29 weeks of pregnancy with either TK- or thymidine kinase-positive (TK+) Cooper virus. All heifers developed fevers of 1 to 2 C during the first week after inoculation. Temperatures of TK+ inoculates were slightly higher and remained above normal a few days longer than in TK- inoculates. Viremia was detected in 5 of 6 TK+ inoculates and in all 6 TK- inoculates. More virus isolations were made from nasal and vaginal swab specimens of TK+ inoculates than from swab specimens of TK- inoculates. All heifers developed virus neutralizing antibody within 14 days after inoculation and antibody titers were similar between the 2 groups. None of the TK- inoculated heifers aborted and their calves did not have neutralizing antibody at birth. Abortion occurred in 5 of 6 heifers given TK+ virus. All aborted fetuses were infected with bovine herpesvirus-1, as demonstrated by virus isolation or detection of viral antigen in fetal tissues. These results indicate that inactivation of the TK gene reduces abortifacient activity of bovine herpesvirus-1.
Show more [+] Less [-]Serologic enzyme-linked immunosorbent assay responses of calves vaccinated with a killed Mycobacterium paratuberculosis vaccine
1991
Spangler, E. | Heider, L.E. | Bech-Nielsen, S. | Dorn, C.R.
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. Widespread use of vaccine may interfere with diagnosis of paratuberculosis and with control programs that are based on serologic tests that measure humoral antibody.
Show more [+] Less [-]Comparison of natural transmission of bovine leukemia virus in Holstein cows of two genetic lines selected for high and average milk production
1991
Detilleux, J.C. | Freeman, A.E. | Miller, L.D.
One hundred and fifty lactating Holstein cows from 2 genetic lines selected for high and average milk production were used in the study. Sera from 6 annual herd tests were analyzed by agar-gel immunodiffusion test for antibodies to bovine leukemia virus. Odds of being seropositive were analyzed by use of stepwise and backward logistic regression procedures. Analysis within birth year revealed that estimated ln odds increased by 0.19/year of age among cows of the high genetic line and by 0.43 among cows of the average genetic line. This was accompanied by a more important cohort effect among high producers than among average producers.
Show more [+] Less [-]