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S J Rodgers

Publications and source records attributed to S J Rodgers.

18 recordsLinked to original sources
PubMed1998

Evaluation of Anaplasma marginale from tick cell culture as an immunogen for cattle.

Anaplasma marginale has been propagated and continuously passaged in an Ixodes scapularis cell line. Anaplasma development was characterized and cultures with a high density of rickettsiae were harvested at a predictable rate. Culture-derived A. marginale (CAM) remained infective for cattle and was used effectively as antigen in diagnostic tests with the sensitivity to identify bovine carriers of A. marginale. This study presents results of an initial trial using the CAM as an immunogen for cattle. CAM was mechanically disrupted, frozen at -70 degrees C, and inactivated with beta-propiolactone. Two intact yearling cattle were immunized with CAM and Freund's adjuvant, receiving 4 subcutaneous injections at 3-4 week intervals. Two control yearling cattle received adjuvant and PBS. Serum samples were evaluated by competitive ELISA (C-ELISA) using CAM as antigen and the standard complement fixation test (CFT). All cattle were subsequently challenged with A. marginale-infected blood from a carrier cow. An additional intact calf was inoculated with live CAM from the same passage and screened by C-ELISA and CFT. Sera collected from immunized cattle were negative or suspicious by CFT throughout the immunization study. The same sera were strongly positive by C-ELISA two weeks after the first injection and throughout the study. All cattle became infected following challenge-exposure with blood, but immunized cattle exhibited longer prepatent periods as well as lower parasitemias and percent reduction of packed cell volumes as compared with the controls. The calf receiving live CAM became infected and underwent a mild clinical reaction with positive C-ELISA and CFT results and did not become clinically ill following blood challenge. This preliminary study suggests that the CAM antigen is highly immunogenic in cattle. Furthermore, the CFT did not identify immunized animals whereas the C-ELISA (using CAM) was highly sensitive for detection of both immunized and infected animals.

Anaplasma↗
PubMed1998

Use of tick cell culture-derived Anaplasma marginale antigen in a competitive ELISA for serodiagnosis of anaplasmosis.

Anaplasma marginale was propagated in a continuous tick cell line and detergent-solubilized infected cells were used as antigen in a competitive ELISA (C-ELISA) for detection of Anaplasma-specific antibody in bovine sera. Positive control sera competed well (> or = 35% inhibition) with an A. marginale-specific monoclonal antibody for binding to this antigen, while negative sera failed to compete (< 35% inhibition). The C-ELISA was compared to the standard complement-fixation test (CFT) using 2,208 bovine sera. Overall, C-ELISA was more sensitive than CFT (24.9% versus 9.4%), mainly because CFT yielded "suspicious" or "anti-complementary" results in 10.5% of the sera and also failed to identify several vaccinated and carrier cattle that were C-ELISA-positive. The apparent agreement between CFT and C-ELISA was 89.6% and the kappa value was 0.6. These results show that this C-ELISA would be a suitable replacement of the CFT as the standard test for detection of A. marginale antibody.

Anaplasma↗
PubMed1998

The development of a semi-automated latex agglutination test for the detection of antibodies to Anaplasma marginale using a cell culture-derived antigen.

Serologic diagnosis of anaplasmosis is currently done by the complement-fixation, ELISA, and card agglutination tests. These tests have utilized A. marginale harvested from bovine erythrocytes as antigen which is often contaminated with erythrocyte stroma. We are currently testing A. marginale propagated in a Ixodes scapularis cell line as antigen for serologic tests. In this study, we report the use of the cell culture-derived A. marginale as antigen for development of a rapid, semi-automated latex agglutination test. Diluted serum and latex (polystyrene microspheres), sensitized with cell culture-derived A. marginale proteins, were dispensed into 96-well microtiter plates. An initial reading of light transmission was recorded by a computer-interfaced scanning autoreader. After 30 minutes, the plates were mixed and read a second time, recording the delta % light transmittance. The sensitized latex microspheres (latex) agglutinated in the presence of A. marginale antibodies, thus producing an increase in light transmittance. In preliminary tests, 724/977 of the sera were positive for A. marginale antibodies with an apparent agreement of 83.3% when compared with the complement-fixation test. Sensitization and sera dilution buffers were shown to have a marked effect on the sensitivity and specificity of this assay. Results will be presented on the optimization of buffers and the testing of sera from experimentally and field-infected cattle.

Anaplasma↗
PubMed1998

Serosurvey of selected viral and bacterial diseases in wild swine from Oklahoma.

Blood samples collected from 120 wild swine (Sus scrofa) in thirteen Oklahoma (USA) counties during 1996 were tested for antibodies against six viral and two bacterial diseases. No antibodies to swine brucellosis, pseudorabies, transmissible gastroenteritis, and vesicular stomatitis were detected. Antibody titers to one or more leptospiral serovars were found in 44% of the samples, the two most frequent serovars being Leptospira interrogans serovars bratislava (29%) and pomona (27%). Antibody against porcine parvovirus and swine influenza virus was detected in 17% and 11% of the swine, respectively. Two samples (2%) were positive for antibody to the recently emerged porcine reproductive and respiratory syndrome virus.

Agglutination Tests↗
PubMed1996

Octadentate catecholamide ligands for Pu(IV) based on linear or preorganized molecular backbones.

Nine new octadentate ligands based on cyclic, spermine (3,4,3-LI), desferrioxamine (DFO), or H-shaped tetrakisamine (penten) molecular backbones were prepared containing catecholamide (CAM), carboxycatecholamide (CAM(C)), or terephthalamide (TAM) chelating units. Mice were injected intravenously with 239Pu(i.v.) citrate, treated with 30 mumol kg-1 of a ligand by intraperitoneal injection at 1 h or by gastric intubation at 3 min, and Pu retention in tissues and Pu transfer to excreta were measured at 24 h. Given by injection, three soluble ligands composed of MeTAM (3,4,3-LIMeTAM, DFO-MeTAM, H(2,2)-MeTAM) reduced Pu retention in the body to 27-28% of control compared with 32 and 37% of control obtained in mice similarly treated with 3,4,3-LICAM(C) or CaNa3-DTPA, respectively. The MeTAM ligands reduced Pu retention in the skeleton as much as an equimolar amount of CaNa3-DTPA, while Pu retention in the liver (on average, 16% of control) was significantly less than was obtained with CaNa3-DTPA (35% of control). Given orally, H(2,2)-MeTAM reduced Pu retention in the whole body to 58% of control compared with reductions to 62 and 94% of control achieved with 3,4,3-LICAM(C) or CaNa3-DTPA, respectively. Penten is both partially preorganized for metal binding and spatially suitable for encapsulation of actinide(IV), and ligands with the penten backbone are easier and less costly to prepare than those based on spermine or DFO. The biological results confirmed that penten is a suitable as well as practical structural backbone for new octadentate ligands. In agreement with the great stability of the ferric complex with MeTAM, as determined in vitro, the small, simple, soluble penten-based octadentate ligand, H(2,2)-MeTAM, was shown to be, overall, the most effective catecholamide ligand for enhancing Pu excretion. Either combined in H(2,2)-MeTAM or separately, the penten backbone and the MeTAM chelating unit are potentially useful additions to the set of backbones and binding units of multidentate ligands identified as effective for in vivo chelation of the actinides.

Administration, Oral↗
PubMed1996

Evaluation of a semiautomated latex agglutination test for the detection of pseudorabies antibody in swine sera.

Rapid screening of large numbers of swine sera for antibody is an essential element in the current eradication program for pseudorabies in the United States. We evaluated a recently introduced commercial semiautomated latex agglutination test (LAT) kit for pseudorabies antibody. A total of 1,191 swine sera were tested using the new procedure and 3 established tests: the manual LAT, the serum neutralization test (SNT), and an enzyme-linked immunosorbent assay (ELISA). There was close agreement among results of semiautomated LAT, the manual LAT, and ELISA but less agreement between semiautomated LAT and SNT. Overall, the sensitivities of the 4 tests were as follows: semiautomated LAT = manual LAT > ELISA > SNT. For 74 samples of known pseudorabies antibody status, the overall specificities were as follows: semi-automated LAT = manual LAT = SNT > ELISA. Because of its relative insensitivity, the SNT should no longer be considered the official "gold" standard for pseudorabies testing in the on-going eradication program. However, because no single test was perfect for all samples, a scheme including 3 tests in the following sequence is recommended: 1) screening using semiautomated LAT or ELISA and 2) confirmation testing of positives by manual LAT and SNT, with any sample that tests positive by any 2 tests being regarded as true positive.

Animals↗
PubMed1994

Seroprevalence of bovine anaplasmosis in Oklahoma from 1977 to 1991.

The prevalence of anaplasmosis in Oklahoma cattle was determined on the basis of the standardized Anaplasma marginale complement fixation test on 20,155 sera submitted to the Oklahoma Animal Disease Diagnostic Laboratory during a 15-year period. Rates of seropositivity ranged from 4.7% to 17.6% on samples submitted for anaplasmosis testing of adult cows. The geographic distribution of recorded cases of anaplasmosis was 35 Oklahoma counties in 1977 and 48 Oklahoma counties in 1991.

Anaplasma↗
PubMed1991

The efficacy of DFO-HOPO, DTPA-DX and DTPA for enhancing the excretion of plutonium and ameriicum from the rat.

A hydroxypridinone derivative of desferrioxamine (Na-DFO-HOPO), a dihydroxamic derivative of diethylenetriaminepenta-acetic acid (ZnNa-DTPA-DX), and DTPA (CaNa3- and ZnNa3-DTPA) were tested at dosages of 30 mumol kg-1 for their ability to remove 238Pu or 241Am from rats after their intravenous injection as citrate or inhalation as nitrate. The most effective treatment regimen for injected Pu was the repeated administration of DFO-HOPO; by 7 days the body content was reduced to 8% of that in untreated animals. Repeated dosages of 3 mumol kg-1 DFO-HOPO were as effective as those of 30 mumol kg-1 DTPA. After inhalation of Pu nitrate, repeated treatment with DTPA, DTPA-DX or DFO-HOPO reduced the body content by 7 days to, respectively, 10, 15 and 31% of those in untreated animals. After inhalation of Am, DTPA-DX and DTPA were equally effective, the body contents being reduced to 7% of control values with repeated treatment. Injection of DFO-HOPO was ineffective for enhancing the elimination of inhaled or injected Am. The results confirm the strategy of examining the use of siderophore analogues for the decorporation of Pu or Am. However, at present DTPA should remain the agent of choice, particularly after inhalation.

Administration, Inhalation↗
PubMed1990

A serologic survey of Oklahoma cats for antibodies to feline immunodeficiency virus, coronavirus, and Toxoplasma gondii and for antigen to feline leukemia virus.

A serologic survey was done on 618 cat sera submitted to the Oklahoma Animal Disease Diagnostic Laboratory between July 1, 1987 and June 30, 1988. The samples were collected from clinically normal and sick cats. The sera were tested for the presence of antibodies to feline immunodeficiency virus by a commercial immunoassay, to a coronavirus by an indirect fluorescent antibody test, and to Toxoplasma gondii by a commercial latex agglutination test and for the presence of feline leukemia virus antigen with one of 3 different commercial assay kits. Ten percent of the sera had antibodies to feline immunodeficiency virus, 35% had antibodies to a coronavirus, and 22% had antibodies to Toxoplasma gondii. Feline leukemia virus antigen was detected in 15% of the sera. Thirty-two percent of the sera had evidence of exposure to 2 or more of the agents.

Animals↗
PubMed1989

A serological survey of Ehrlichia canis, Ehrlichia equi, Rickettsia rickettsii, and Borrelia burgdorferi in dogs in Oklahoma.

Serum samples from 259 dogs were tested for antibodies to Ehrlichia canis, Ehrlichia equi, Rickettsia rickettsii, and Borrelia burgdorferi using the indirect fluorescent antibody test. The sera were obtained from submissions to the Oklahoma Animal Disease Diagnostic Laboratory during a 14-month period from June 1986 through July 1987. The rate for positive antibody titers to E. canis was 53%, to E. equi was 33%, to R. rickettsii was 38%, and to B. burgdorferi was 18%. Higher percentages of sera serologically positive to E. canis were found in the spring through the fall months, but there were no seasonal variations for E. equi, R. rickettsii, and B. burgdorferi. There was no consistent pattern of titers to the 4 antigens when age-groups of the dogs were compared. Forty-four different breeds were tested.

Age Factors↗
PubMed1976

Development of an air purifier for personnel cubicles.

An air purifier was developed for tunnel, toll and garage booths or cubicles. Catalytic oxidation, activated carbon and a HEPA filter are used to scrub out CO, hydrocarbons, NO2 and particulates. Tunnel tests showed these air impurities were adequately removed.

Air Conditioning↗
PubMedDate not supplied

Preliminary studies of primary ostrich fibroblasts for the isolation of ratite viruses.

An ostrich egg at 21 days of development was used to propagate primary embryo cell cultures. Primary cultures of skeletal muscle cells (for fibroblasts) were prepared by routine typsinization techniques. The ostrich embryo fibroblasts were tested for their ability to propagate stock avian viruses of infectious bronchitis virus, paramyxiovirus-1 (PMV-1), PMV-2, PMV-3, infectious bursal disease virus, quail bronchitis virus, avian reovirus, turkey coronavirus, and two ostrich-originating specimens (one of which was a possible coronavirus identified by electron microscopy). Cytopathic effects were seen by light microscopy in cell cultures inoculated with PMV-1, turkey coronavirus, and the two ostrich specimens. Hemaglutinating titers of 4 or more were determined for PMV-1, turkey coronavrius, and the two ostrich specimens after inoculation onto monolayers of ostrich embryo fibroblasts. Hemagglutination-inhibition tests confirmed the identification of PMV-1 when homologous antisera were used as the specific inhibitor. Bovine coronavirus antisera inhibited the hemagglutination of one of the cultured ostrich specimens.

Animals↗