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Biomedical subjects

G W Pugh

Publications and source records attributed to G W Pugh.

72 records · Page 4Linked to original sources
PubMed1975

Infectious bovine keratoconjunctivitis: a ring device designed for prolonged retention in the bovine eye.

A study was conducted to determine whether treatment devices could be designed for prolonged retention in the eyes of cattle. Experimental design ring devices were compared relative to their ease of insertion, induction of adverse tissue reaction, and period of retention. The ring devices were also compared with commercially available devices used in human eyes. Ring devices having a circumference smaller than that of the conjunctival sac, but larger than that of the globe of the eye, were easy to insert, caused a minimal tissue reaction, and were retained by the eye up to 19 days. The authors suggest that a development using the ring design and an erodable matrix containing an antibacterial agent could lead to a possible method for the treatment of obstinate infections, such as infectious bovine keratoconjunctivitis (IBK) and Moraxella bovis carrier states in cattle.

Animals↗
PubMed1975

Experimentally induced infectious bovine keratoconjunctivitis: relationship of vaccination schedule to protection against exposure with homologous Moraxella bovis culture.

Calves were intramuscularly vaccinated with a formalin-killed Moraxella bovis culture. They were given 3 doses of the vaccinal culture at 3 different intervals between injections, as follows: 7-day intervals (group I), 14-day intervals (group II), an21-day intervals (group III); 14 days after the 3rd vaccinal dose was given, calves in all groups were challenge exposed to virulent homologous M bovis. The challenge bacterium became established in all (100%) of the control (group IV, N equals 8) and group I (N equals 8) calves, in 7 (87%) of the group II calves (N equals 8), and in 5 (62%) of the group III (N equals 8) calves. Signs of infectious bovine keratoconjunctivitis (IBK) developed in 8 (100%) of the controls, in 6 (75%) of the group I calves, in 1 (12%) of the group II calves, and in 2 (25%) of the group III calves. These results indicate that at least 14 days should be allowed between successive doses of this experimental vaccine.

Animals↗
PubMed1973

The pathophysiological effects of Moraxella bovis toxins on cattle, mice and guinea pigs.

In three experiments, cattle, mice and guinea pigs were inoculated with viable cultures of Moraxella bovis or fractions of this organism. Fractions were obtained by disruption of cells with a fractionator at 20,000 pounds per square inch, and separating the cell wall and cell sap fractions by differential centrifugation. Cell sap fractions were further separated by ultra-centrifugation, heating and precipitation with (NH(4))(2) SO(4). Different fractions induced different pathophysiological manifestations. The cell wall fractions caused localized lesions (necrosis) at the site of injection, and emphysema and congestion of the lungs. Cell sap fractions induced a "shock syndrome," as well as hemorrhage and inflammation of the intestines, hemorrhage and congestion of lymph nodes, liver, adrenal and spleen. Cell sap also induced conjunctivitis in mice and guinea pigs, and periocular edema, myosis, ocular pruritus and lacrimation in cattle. The authors suggest that M. bovis probably produces endotoxins and exotoxins as well as possibly a specific oculopathic substance, but more definitive work is needed to confirm this. They caution that consideration of these toxins should be made in any application of M. bovis for vaccines or other immunological studies.

Animals↗
PubMed1971

Bovine infectious keratoconjunctivitis: serological aspects of Moraxella bovis infection.

A modification of a gel diffusion precipitin test (GDPT) was used to detect antibodies for Moraxella bovis (M. bovis) in the sera of cattle affected with bovine infectious keratoconjunctivitis (BIK). The test was also used for the detection of sequential antibody development in cattle vaccinated with cultures of M. bovis. Also, strains of M. bovis isolated from cattle herds affected with BIK were characterized serologically as a part of an identification scheme using the test.A comparison of the antigenic properties of various strains of M. bovis and M. bovis-like organisms was conducted using the test. The results indicated that there might be antigenic relationships between M. bovisand M. bovis-like organisms such as Moraxella liquefaciens, Moraxella nonliquefaciens, an unidentified hemolytic diplococcus, Mima polymorpha, Mima polymorpha var. oxidans and Herellea vaginicolaThe authors suggest that the GDPT can be used for serological studies of BIK, and the identification and antigenic analysis of M. bovis. They indicate, however, that a more definitive study is needed to evaluate the reliability of the test for quantitative work.

Animals↗
PubMed1970

Comparison of the virulence of various strains of Moraxella bovis.

The relative virulence of various strains of Moraxella bovis (M. bovis) was studied using the eyes of mice and cattle. The investigation consisted of three separate experiments. Experiments I and II involved a study on the effects of (1) different methods of growth and (2) serial blood agar passaging on the virulence of M. bovis. Experiment III involved a study on the relative virulence of different strains of M. bovis and M. bovis-like organisms. Strains of M. bovis and M. bovis-like organisms varied in their pathogenicity for mice. However, different methods for preparation of exposure cultures of M. bovis did not influence the disease produced.

Agar↗