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Biomedical subjects

C Burrells

Publications and source records attributed to C Burrells.

8 recordsLinked to original sources
PubMed1979

Inability of passively acquired antibody to protect lambs against experimental pasteurellosis.

An experimental model of pneumonic pasteurellosis in sheep was used to investigate the role of serum antibody in resistance to this disease. Lambs which had been vaccinated with a sodium salicylate extract of Pasteurella haemolytica type A1 were protected against challenge with PI3 virus followed by P. haemolytica type A1 7 days later. The majority of untreated lambs and lambs which had received either 200 ml of antiserum to P. haemolytica or 200 ml of control serum intraperitoneally 18 h before infection with P. haemolytica type A1 succumbed to the challenge. Lymphocytes from vaccinated lambs showed a specific proliferative response when exposed to P. haemolytica type A1 sodium salicylate extract, and this response increased after exposure of these animals to P. haemolytica type A1 in aerosol. The results indicate that the humoral immune response alone is incapable of affording protection against experimental pasteurellosis and that cell-mediated immunity may play an important part in resistance to this disease.

Animals↗
PubMed1979

A serological comparison of Pasteurella haemolytica vaccines containing different adjuvants.

Five adjuvants were compared for their ability to enhance the serological response of sheep to capsule extract of Pasteurella haemolytica biotype A serotype 6. Vaccines of this antigen were inoculated with incomplete Freund's adjuvant, complete Freund's adjuvant, incomplete Freund's adjuvant containing a water soluble extract of Mycobacterium tuberculosis, aluminium hydroxide gel or a combination of aluminium hydroxide gel and incomplete Freund's adjuvant. This latter vaccine induced significantly higher titres of antibody as measured by an indirect haemagglutination test than did any of the other vaccines. The aluminium hydroxide gel alone was shown to be the poorest adjuvant. The local reactions at the sites of inoculations produced by the aluminium hydroxide gel in incomplete Freund's adjuvant vaccine were not severe and were not detectable beyond one month after vaccination in the majority of the sheep.

Adjuvants, Immunologic↗
PubMed1978

Reactivity of ovine lymphocytes to phytohaemagglutinin and pokeweed mitogen during pregnancy and in the immediate post-parturient period.

Lymphocytes from sheep in late pregnancy and at parturition showed markedly impaired proliferative responses to phytohaemagglutinin (PHA) in vitro when cultures were supplemented with foetal bovine serum (FBS), as compared to the responses of lymphocytes from non-pregnant sheep, sheep at 40 days of gestation and sheep at 80 days of gestation. Similar responses to PHA were observed when the medium was supplemented with autologous plasma (AP), although the responses were of a lower order. In both cases elevated responses to PHA were apparent at 10 days post-parturition. The response with FBS was more marked than with AP. Progressive reduction of lymphocyte responses to pokeweed mitogen (PWM) in the presence of FBS and AP were less obvious, although it was still apparent that responses to PWM were depressed at 120 days of gestation and at parturition, when compared with lymphocyte responses during early pregnancy (at 40 days and 80 days of gestation). The difference was much more apparent with AP than with FBS and responses during early pregnancy were markedly higher than those with FBS. An increase in lymphocyte responsiveness to PWM 10 days post-parturition was evident whether FBS or AP was incorporated in the cultures. The response with FBS was again more marked than with AP.

Animals↗
PubMed1976

The assessment in sheep of an inactivated vaccine of parainfluenza 3 virus incorporating double stranded RNA (BRL 5907) as adjuvant.

The serological responses of conventionally reared sheep were compared after vaccination with inactivated parainfluenza 3 (PI3) virus incorporated in three different adjuvants. Inactivated PI3 virus with the double-stranded RNA, BRL 5907 in an oil emulsion was shown to stimulate higher serum antibody titres over the first 5 weeks after vaccination than virus with and without BCG emulsified in oil. The ability of this vaccine to protect specific pathogen-free lambs against challenge with PI3 virus was examined in a second experiment. In this experiment the vaccine stimulated virus neutralizing and haemagglutination inhibiting antibodies in the serum. After intranasal and intratracheal inoculation with PI3 virus at challenge, vaccinated lambs showed no clinical illness and virus isolation was confined, except in one lamb, to the first two days. In contrast, unvaccinated lambs developed respiratory disease and virus was isolated daily for 7 days after challenge.

Adjuvants, Immunologic↗
PubMed1976

Maternal immunoglobulins and parainfluenza 3 virus inhibitors in the nasal and lachrymal secretions and serum of newborn lambs.

Concentrations of IgG, IgM and IgA were measured in the serum, nasal secretions and lachrymal secretions of suckled newborn lambs. The major immunoglobulin constituent of precolostral serum was IgM. Maternal immunoglobulins, of which IgG was predominant, reached peak values on day 1 of life and then declined over the next 3 weeks. Half lives were calculated as: IgG, 13-7 days; IgM, 4-1 days; and IgA 1-8 days. No immunoglobulin was detectable in nasal or lachrymal secretions prior to sucking but IgG was present in all samples of these secretions obtained approximately 24 hr after first sucking. IgG was present in nasal washings from suckled lambs, reared either naturally or on immunoglobulin-free milk substitute and levels declined as the lambs grew older. IgM and IgA did not appear consistently in the secretions until lambs were 2-3 weeks old. It was concluded, therefore, that colostral IgG reaches the nasal and lachrymal secretions of the newborn lamb. However, because the ewes in this experiment had only low serum titres, no maternal antibody to parainfluenza 3 virus (PI3) was detected in the nasal secretions of the lambs, although non-specific inhibitors were present. It is suggested, however, that low levels of maternal antibody in the secretions may play a valuable role in preventing respiratory virus infections of young ruminants before active local production of IgA and IgM begins at 2 to 3 weeks of age.

Animals↗
PubMed1976

Immunoglobulins in the serum and nasal secretions of lambs following vaccination and aerosol challenge with parainfluenza 3 virus.

Serial changes in the concentrations of IgM, IgG and IgA were compared in specific pathogen free (SPF) lambs which had been vaccinated with live or inactivated parainfluenza 3 virus (PI 3) by either intramuscular (IM) or intranasal (IN) routes followed by aerosol challenge with PI 3. In the serum, an increase in IgM was associated with the primary antibody response to the aerosol challenge, whereas increased IgG was associated with the secondary antibody response. No changes in immunoglobulin concentrations were observed in the nasal secretions of lambs administered live or inactivated virus IM or IN without adjuvant. Marked increases in IgG were found in the serum and nasal secretions of lambs vaccinated IM with inactivated virus in Freund's complete adjuvant (FCA) and fractionation by gel filtration confirmed that the antibody was associated with IgG in both these fluids.

Administration, Intranasal↗
PubMed1975

Immunoglobulins, antibodies and inhibitors of parainfluenza 3 virus in respiratory secretions of sheep.

Virus neutralising and haemagglutination inhibiting (HI) activities were monitored in the serum, nasal secretions and tracheo-bronchial secretions of lambs infected with Parainfluenza virus type 3 (PI3). HI activity was found in the secretions of both control and infected lambs, whereas neutralising antibody was found only in nasal secretions from infected lambs. Fractionation revealed that most of the HI activity in the secretions was due to a large molecular weight protein which also inhibited the haemagglutination (HA) of Parainfluenza virus type 1 (PI1) and type 2 (PI2) and Newcastle disease virus (NDV). This inhibitory activity was partially sensitive to receptor destroying enzyme (RDE). IgA antibodies specific for PI3 were also found in the respiratory secretions. However no increase in IgA levels was detected in the nasal secretions of the infected lambs. It is suggested that in certain reports non-specific inhibitors present in the nasal secretions of calves, may have been confused with PI3 specific IgA antibody.

Animals↗