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Biomedical subjects

R F Ross

Publications and source records attributed to R F Ross.

At least 73 records · Page 4Linked to original sources
PubMed1977

Modified metabolic-inhibition test for detection of antibodies to Mycoplasma hyosynoviae in swine serum.

A modification of the metabolic inhibition (MI) test was used for detection of antibodies against Mycoplasma hyosynoviae in convalescent swine serum. Supplementation of the MI system with 1% unheated normal rabbit serum, as well as 6% unheated normal guinea pig serum was required for detection of MI antibodies in early phase, postinfection serum and markedly improved detection of MI antibodies in late phase, postinfection serum. Factor(s) supplies by rabbit serum was not supplied by unheated normal swine serum.

Animals↗
PubMed1977

Immunogenicity of experimental Streptococcus equisimilis vaccines in swine.

The protective and complement-fixing antibody immune responses to Streptococcus equisimilis vaccines were evaluated in young, surgically derived, colostrum-deprived swine. Comparable levels of protection against live S equisimilis challenge exposure developed in response to sonic-extract, acid-extract, and whole-cell vaccines combined with incomplete Freund adjuvant. The extract vaccines induced higher levels of complement-fixing antibody than did killed, whole cells. Protection, as well as complement-fixing antibody immune responses, were comparable when swine were given doses of vaccine beginning at 3 or 8 weeks of age.

Animals↗
PubMed1976

"Sweet itch".

Explore the source record for details and available documents.

Animals↗
PubMed1975

A field study of coliform mastitis in sows.

Three sows with agalactia and mastitis were compared with 3 normally lactating sows at 8, 16, 24, and 32 hours postpartum. Bacteriologic examination of milk resulted in isolation of Klebsiella pneumoniae or Escherichia coli from affected glands of all 3 agalactic sows. Milk from clinically normal glands of affected sows and from glands of normal sows was culture-negative for coliforms. Affected sows had higher rectal temperatures and lower milk yields, and pigs from affected sows had lower mean weights, but these differences were not significant. Mean total white blood cell counts and plasma protein to fibrinogen ratios were lower in mastitic sows at all 4 periods; differences were significant at certain periods in both cases. Evidence indicated that leukopenia appeared early, 8 to 16 hours postpartum, and was followed by increasing plasma fibrinogen content. Packed cell volumes and plasma concentrations of corticoid, estrone, and estradiol did not differ. Plasma progesterone content was higher in mastitic sows at all periods, but the differences were not significant.

Adrenal Cortex Hormones↗
PubMed1975

Purification and serological characterization of a type-specific antigen of Streptococcus equisimilis.

A microtiter complement fixation (CF) procedure was developed for use in detection of antibodies in sera of swine and rabbits vaccinated with Streptococcus equisimilis. Crude ultrasonic as well as acid-extracted preparations contained CF antigen, but the ultrasonic procedure resulted in a higher yield of active antigen. Evidence of serotype specificity with varying degrees of cross reactivity was detected with the CF procedure when representative strains of four different serotypes of S. equisimilis were compared by using their respective unadsorbed antisera. Fractionation of crude sonic extract or acid extract by centrifugation, precipitation with ammonium sulfate, and chromatography on carboxymethyl cellulose yielded a purified, type-specific antigen that reacted only with the homologous antiserum in the CF test and formed a single band by immunodiffusion. Complement-fixing antibodies in immune swine sera were predominately immunoglobulin G.

Animals↗
PubMed1975

Joint changes in lameness of confined swine.

Hampshire swine reared in confinement developed spontaneous lameness. In a comparison of lame swine with normal Hampshire and normal Yorkshire swine, there were no substantial differences in the gross or microscopic appearance of synovial membranes or volume of synovia per joint. Somatic cell count in synovia of lame Hampshires was higher than that of normal Hampshires; however, in normal Yorkshires, cell count was higher than that of either group of Hampshires. Total protein and total lactic dehydrogenase (LDH) values were significantly higher in synovia of lame swine than in synovia of normal swine, as were also the gamma-globulin and LDH5 values. Hampshire swine seemed to be more heavily muscled than the Yorkshires, but the difference was not significant. In a 2nd comparison, joints of the swine were regrouped as normal or abnormal, on the basis of macroscopic appearance. Significant differences were not detected in total volume of fluid per joint, number of somatic cells per milliliter of fluid, total protein, or the 3 microscopic lesion scores in this comparison. Total LDH was significantly higher in the abnormal joints.

Animals↗
PubMed1975

Determination of sensitivity of Mycoplasma hyosynoviae to tylosin and selected antibacterial drugs by a microtiter technique.

A microtiter technique was used for determination of the sensitivity of Mycoplasma hyosynoviae to antibiotics and other drugs. Use of a biphasic agar-broth medium in microtiter plates allowed direct visualization of growth. Results were more reproducible with this system than when broth alone was used and evaluation based on color change was required. Attempts to adapt the test for use with Mycoplasma hyorhinis were not successful. Minimal inhibitory concentrations of 12 drugs and drug combinations for 12 strains of M. hyosynoviae are presented. Drugs with the lowest minimal inhibitory concentrations were tylosin (0.37 mcg/ml)and lincomycin (0.88 mcg/ml), both of which have been used for treatment and control of M. hyosynoviae arthritis. Comparison of the minimal inhibitory concentrations of tylosin for 43 isolates of M. hyosynoviae obtained in 1959 and 1960 and from 1966 through 1971 indicated the possibilty of decreasing sensitivity to the drug although differences between recent isolates and earlier ones were not statistically significant.

Acetates↗
PubMed1972

Antigenic type-specificity of swine isolates of Streptococcus equisimilis.

Isolates of a Lancefield Group C organism, Streptococcus equisimilis, of sow reproductive tract and young swine joint origin were found to possess type-specific antigens. Capillary precipitin and immunodiffusion tests, done with acid extracts and cross-absorbed rabbit antisera, revealed four serotypes among 62 of 64 isolates. Extracts of two swine isolates of S. equisimilis and other Lancefield Group C strains including S. equi, S. zooepidemicus and three previously established types of S. equisimilis of human origin did not react with any of the four type-specific sera. Antigens responsible for type-specificity were heat-stable and sensitive to trypsin.

Animals↗
PubMed1972

Chronological development of Mycoplasma hyorhinis and Mycoplasma hyosynoviae infections in cultures of a swine synovial cell strain.

The sequential development of Mycroplasma hyorhinis and Mycoplasma hyosynoviae was observed in cultures of a swine synovial fluid cell strain. An early transitory filamentous phase was observed with M. hyorhinis infection followed by the development of cell-associated, relatively large, round structures and some ring forms. Infection with M. hyorhinis was characterized by a generalized distribution of the organism and a severe cytopathic effect. Infection with M. hyosynoviae was represented by the development of circumscribed foci of small pleomorphic structures and a milder effect on the cells. At a high multiplicity of infection, this organism became associated with the cytoplasmic membranes of the cells.

Animals↗