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Biomedical subjects

C S Eidson

Publications and source records attributed to C S Eidson.

At least 37 records · Page 2Linked to original sources
PubMed1978

In vivo and in vitro studies on the effect of gentamicin sulfate on the efficacy of the turkey herpesvirus vaccine.

In vitro studies indicate that the titer of the cell-free or cell-associated turkey herpevirus (HVT) vaccine was not appreciably reduced when incubated with .1, .2, or .3 mg of gentamicin sulfate for up to 2 hr. However, the titer of both the cell-free and cell-associated HVT vaccines was reduced when incubated with .4 mg of gentamicin sulfate for 2 hr. However, in vivo studies show that the incidence of Marek's disease (MD) in chickens which were vaccinated with the cell-free or cell-associated HVT vaccine which had been incubated with ,1, .2, .3, or .4 mg of gentamicin sulfate up to 2 hr was not increased when compared to chickens receiving only the HVT vaccine. The results of other laboratory studies also show that there was no increase in the incidence of MD when comparing chickens which received either 1360 or 6360 PFU of cell-free HVT vaccine or 1250 or 5690 PFU of cell-associated HVT vaccine to those vaccinated with the same doses of cell-free or cell-associated HVT vaccine containing .2 mg of gentamicin sulfate.

Animals↗
PubMed1978

Effect of aflatoxin on the humoral and cell-mediated immune systems of the chicken.

Chickens fed 2.5 microgram of aflatoxin/g of diet from 2 to 4 weeks of age or from hatching to 4 weeks were deficient in cell-mediated immunity, as measured at 4 weeks of age by the graft-versus-host reaction. Delayed-type hypersensitive skin reactions to tuberculin were also reduced in chickens given dietary aflatoxin from hatching to 7 weeks of age. Humoral immunity, as measured by the ability of 4-week-old chicks to produce natural agglutinins to rabbit red blood cells, was not significantly altered by dietary aflatoxin. A significant decrease in concentrations of serum immunoglobulins (Ig) IgG and IgA, but no IgM, however, did occur in chicks given dietary aflatoxin from hatching to 4 weeks or between 2 and 4 weeks of age. Aflatoxin consumption from 0 to 2 weeks of age produced no marked effect on either cell-mediated or humoral immunity in 4-week-old chicks.

Aflatoxins↗
PubMed1977

Factors influencing the appearance of antibody in tracheal washes and serum of young chickens after exposure to Newcastle disease virus.

The development of plaque-neutralizing antibody in tracheal washes and hemagglutination inhibition antibody in serum was followed after intratracheal and intranasal or intramuscular inoculation of 1-, 14-, or 28-day-old chicks with a lentogenic strain of Newcastle disease virus (NDV). Serum antibody could be detected between 7 and 10 days after intratracheal and intranasal vaccination in birds either with or without maternal antibody to NDV. However, among the 1-day-old group only birds without maternal antibody showed an antibody response after intramuscular inoculation. All birds possessing either actively or passively acquired serum antibody showed a sharp rise and subsequent decline of anti-NDV activity in tracheal washes between 4 and 10 days after intratracheal or intranasal vaccination. Using radiolabeled chicken immunoglobulin injected intravenously as a tracer, it was shown that this initial peak of anti-NDV activity in tracheal washes could be accounted for by enhanced transudation of serum antibody. The transudation of serum antibody coincided with the course of viral pathology observed in the tracheae of infected birds. Neutralizing antibody in tracheal washes beyond 10 to 14 days postvaccination was, most likely, porduced locally, in the respiratory tract.

Administration, Intranasal↗
PubMed1977

Effect of bursectomy and depletion of immunoglobulin A on antibody production and resistance to respiratory challenge after local or systemic vaccination of chickens with Newcastle disease virus.

Surgical removal of the bursa of Fabricius from newly hatched chicks resulted in a depletion of immunoglobulin A (IgA) from serum and bile of 55 and 67% of the birds, respectively, up to 11 weeks of age. The occurrence of IgG and IgM in serum and IgG in bile was not affected by neonatal bursectomy (Bx). A slight compensatory increase in the occurrence of IgM in bile was noted in Bx birds. When exposed to a lentogenic strain of Newcastle disease virus by either intramuscular or intratracheal routes, the Bx group produced a level of serum hemagglutinating antibody and tracheal wash neutralizing antibody indistinguishable from that reached in the sham-Bx group. All of the vaccinated Bx birds challenged by intratracheal exposure to a velogenic strain of Newcastle disease virus remained healthy. These results suggest that IgA is not essential for the development of immunity in the chicken and that other locally produced immunoglobulins or transuded serum antibody may protect the tracheal mucosa in the absence of IgA.

Aerosols↗
PubMed1977

Comparison of the efficacy and transmissibility of conventional NDV vaccines and vaccines prepared after back-passage through chickens.

In laboratory trials B1 and Lasota stains of Newcastle disease virus (NDV) back-passaged in chickens were found to have a greater spreading potential than presently available B1 and Lasota vaccines. Although the regular B1 and Lasota strains of NDV gave a routine serologic response when administered to 4-week-old chickens via the water, both vaccines had a low spreading potential since the geometric mean titer of the birds in contact with the B1 vaccinated birds did exceed 3.4 and the HI response of the nonvaccinated birds placed with the Lasota vaccinated birds did not exceed 4.1. The results from this study also indicate that these back-passaged vaccines elicit higher HI titers and are possibly more invasive than the regular B1 and Lasota vaccines. The data also suggest that the Lasota strain possesses a slightly greater spreading potential than the B1 strain of NDV.

Administration, Oral↗
PubMed1977

Effect of infectious bursal disease on the severity of Eimeria tenella infections in broiler chicks.

A study was initiated to determine whether prior exposure to infectious bursal disease virus (IBDV) influenced the susceptibility of young broiler chicks to Eimeria tentella infections. When one-day-old chicks infected with IBDV were subsequently challenged with E. tenella at 7 days of age, they suffered significantly higher mortality and lesion scores than their hatchmates which were not exposed to IBDV. Initial exposure to IBDV also had an effect on the development of E. tenella induced hemorrhaging. Hemorrhaging commenced late on the third day following E. tenella inoculation in chicks infected with both IBDV and E. tenella, while bleeding did not occur in the E. tenella alone group until late on the fourth day post-coccidial challenge. No significant differences in weight gains at 7 or 14 days after E. tenella infection were observed between chicks receiving the double infection and those given only E. tenella.

Animals↗
PubMed1977

Effect of infectious bursal disease virus on the immunological responsiveness of the chicken.

The immunological response of chickens infected at 28 days of age with infectious bursal disease virus (IBDV) was examined. Cellular immunity was studied by the graft-versus-host reaction and delayed type hypersensitivity skin reactions to tuberculin. Antibody responses to sheep red blood cells (S-RBC's) were tested by a direct hemagglutination test. Circulating levels of immunoglobulins (Ig's) IgM, IgG and IgA were monitored by the radial immunodiffusion test. The results of the graft-versus-host reaction and delayed type hypersensitivity reactions were similar for both the infected and control chicks. IBDV significantly reduced the primary antibody response to S-RBC's, but had no marked effect on the secondary antibody response. Chicks infected with IBDV had normal levels of serum IgM and IgG, but significantly lower levels of IgA when compared to uninfected control birds.

Animals↗
PubMed1977

Application of the cell-free turkey herpesvirus vaccine by the aerosol route for the prevention of Marek's disease in chickens.

In field trials approximately 300,000 birds were vaccinated against Marek's disease (MD) by aerosol spray with 1,000 to 5,000 PFU of cell-free HVT vaccine per chick. Chicks were sprayed in the trays of the hatchers which still contained dust and down after hatching. Prior to spraying, the incoming and outgoing air ducts were closed. The chicks were sprayed for 12--15 min. with HVT in 250 to 300 ml. of diluent, and after completion of spraying the chicks remained in contact with the aerosol for approximately 10 minutes. In birds vaccinated by aerosol spray the incidence of MD ranged from 0.0% to 24.4%; while the incidence of MD in birds vaccinated by subcutaneous inoculation varied from 0.02 to 23.9%. In trial 1 the incidence of MD in birds vaccinated by aerosol spray was essentially the same as those vaccinated by subcutaneous inoculation; whereas, the incidence of MD (Trial 2 and 3) was higher in birds vaccinated by aerosol as compared to chickens vaccinated by subcutaneous inoculation.

Aerosols↗
PubMed1977

Effect of infectious bursal disease on the response of chickens to Mycoplasma synoviae, Newcastle disease virus, and infectious bronchitis virus.

At 35 days of age, chickens which as 1-day-old chicks were inoculated with the infectious bursal disease virus (IBDV) had significantly lower antibody titers against Mycoplasma synoviae, Newcastle disease virus, and infectious bronchitis virus than did those never inoculated with IBDV. The IBDV also had a marked effect on the development of air-sac lesions. Birds infected with IBDV that were later inoculated with M synoviae (day 14), Newcastle disease virus (days 14 and 28) experienced an increased incidence and greater seversity of airsacculitis than did chicks which were not exposed to IBDV.

Air Sacs↗
PubMed1977

Specific suppression of the bursa-dependent immune system of chicks with infectious bursal disease virus.

Chicks which had been inoculated with infectious bursal disease virus (IBDV) at 1 day of age had a severe depression of bursa-dependent humoral immune functions by day 42. Antibody responses against rabbit red blood cells or to immunization with bovine serum albumin were significantly suppressed. In contrast, chicks inoculated with IBDV at 21 days of age produced near normal antibody responses as compared with the responses in noninfected control chicks. The IBDV had no significant effect on the thymus-dependent cellular responses as measured by skin graft rejection or delayed type hypersensitivity reactions to tuberculin.

Aging↗
PubMed1976

Vaccination of chickens against Marek's disease with the turkey herpesvirus vaccine using a pneumatic vaccinator.

A pneumatic vaccinator has been successfully used to administer cell-associated turkey herpesvirus (HVT) vaccine without a loss in titer due to the pressure required to administer the vaccine. Laboratory studies have also shown that chickens vaccinated with graded doses of the HVT vaccine using doses as low as 41 PFU offered protection against Marek's disease (MD) when compared to the unvaccinated controls. The pneumatic vaccinator has also been successful in administering a combination of HVT vaccine and tissue culture fowl pox vaccine. Vaccinated birds were protected against challenge with virulent MD virus as well as fowl pox virus. Antibiotics such as spectinomycin pentahydrate or lincomycin hydrochloride monohydrate and spectinomycin sulfate tetrahydrate were used in combination with the HVT and fowl pox vaccine and none of the antibiotics appear to have an adverse effect on the efficacy of either vaccine.

Animals↗
PubMed1976

Efficacy of intratracheal administration of Newcastle disease vaccine in day-old chicks.

Groups of day-old chicks with varying levels of parental antibody were vaccinated against Newcastle disease (B1 strain) with a commercially available device which simultaneously debeaks the chick and emits a fine spray of vaccine into its trachea. Some groups were also vaccinated (B1 or Lasota strain) with a commercially available vaccine sprayer at 9 days, 14 days, or 9 and 25 days of age. Response to vaccine was evaluated once each week during the experimental period of approximately 8 weeks HI titers were determined and 10 chicks were challenged with the Texas GB strain of Newcastle disease virus. In chicks with low to moderate levels of maternal antibody a satisfactory antibody response was attained by vaccination at 1 day of age, and in most cases resistance to challenge was evident by 3 weeks of age. Intratracheal vaccination of chicks with extremely high levels of maternal antibody had a minimal antibody response. All groups of chicks spray vaccinated at 9, 14, or 9 and 25 days of age showed a marked increase in antibody titer regardless of whether they had been vaccinated at 1 day of age.

Aerosols↗
PubMed1976

A comparison of various routes of Newcastle Disease vaccination at one day of age.

Groups of 100 one-day-old chicks with moderate levels of maternal antibody were vaccinated with the B1 strain of Newcastle disease virus subcutaneously, intratracheally, intraocularly or by aerosol or were left unvaccinated. Certain of these groups were revaccinated at 9 or 9 and 28 days or at 14 or 14 and 28 days with the LaSota strain of Newcastle disease virus. Vaccination by all routes at one day of age resulted in an antibody response and increased resistance to challenge. The most effective route was by aerosol followed by the intraocular method. Intratracheal administration or subcutaneous inoculation led to a marginal response. Aerosol administration at 9 or 9 and 28 days or at 14 or 14 and 28 days gave adequate antibody responses and resistance to challenge.

Aerosols↗
PubMed1976

Long term studies comparing the efficacy of cell-free versus cell-associated HVT vaccines against Marek's disease.

In long-term field trials lasting approximately 12 months attempts were made to determine whether the cell-free HVT vaccine was as effective in reducing MD losses as the cell-associated HVT vaccine. Four trials were conducted in which flocks were vaccinated with either the cell-free or the cell-associated HVT vaccine. The cell-free HVT vaccine was as safe and effective in preventing MD as the cell-associated HVT vaccine. Although there were some losses due to MD in all flocks, there were also losses due to lymphoid leukosis, multiple hemangioma, liposarcoma or coccidiosis. Egg production was essentially the same in flocks vaccinated with the cell-free HVT vaccine as in those vaccinated with the cell-associated HVT vaccine.

Animals↗
PubMed1976

Application of the turkey herpesvirus vaccine by the aerogenic route for the prevention of Marek's disease.

Recently in laboratory and field trials, birds were vaccinated with cell-free HVT vaccine by aerosol spray. In laboratory trials, birds vaccinated by aerosol spray were as well protected against challenge with virulent MD (GA isolate) as those vaccinated by subcutaneous inoculation. Birds were vaccinated with a sprayer (Spraying Systems Company, Wheaton, Illinois) which emits a particle size in which 90% are less than microns. The chicks were sprayed with 1,000 to 10,000 PFU per bird dose and remained in contact with the aerosol for 30-60 min. Turkey herpesvirus was isolated from the blood or kidney of these birds as early as 7 to 10 days postvaccination. In field trials approximately 300,000 birds have been vaccinated by aerosol spray with between 2,000 to 5, 000 PFU of cell-free HVT vaccine per chick. Chicks were sprayed while they were in the trays of the hatchers which still contained the dust and down which remained after hatching. Prior to spraying, the incoming and outgoing aid ducts were closed. The chicks were sprayed for 12-15 min with 250-300 ml of diluent, and after completion of spraying the chicks remained in contact with tha aerosol for an additional 5 to 8 min. In the birds vaccinated by aerosol spray the incidence of MD in the processing plant varied from 0.0% to 23.4%, while the incidence of MD in birds vaccinated by subcutaneous inoculation varied from 0.02 to 23.9%. Overall the incidence of MD in birds vaccinated by aerosol spray was essentially the same as those vaccinated by subcutaneous inoculation.

Aerosols↗
PubMed1976

Aerosol administration of Newcastle disease vaccines at one day of age.

Newcastle disease vaccines were administered at one day of age by 3 general procedures: 1) discharge of a vaccine aerosol over chicks confined in an enclosed space, 2) aerosol adminstration in a poultry house, 3) a commercial device which emits a fine spray into the nasopharynx while the chick is being debeaked. From this work the following conclusions have been drawn: 1) All 3 methods are of some value with respect to the development of antibody titers and resistance to challenge. 2) The efficacy is universely proportional to the maternal antibody titer. 3) Aerosol vaccination into an enclosed air space is superior to the other methods tested. 4) Day-old vaccination is useful primarily in conferring some early resistance until a subsequent aerosol vaccination at 9-14 days of age confers additional protection. Other important factors include strain of vaccine, vaccine titer, the nature of the diluent, and site of the aerolized particles.

Administration, Oral↗
PubMed1975

Efficacy of lyophilized turkey herpesvirus vaccine against Marek's disease in broilers.

Field trials involving approximately 1,250,000 chickens vaccinated with cell-free turkey herpesvirus (HVT) vaccine and 635,000 chickens vaccinated with cell-associated HVT vaccine howed both vaccines equally effective in reducing condemnations (attributable to Marek's disease) at the poultry processing plant. Vaccinated chickens were progeny of hens vaccinated at 1 day of age with cell-associated HVT vaccine. The maternal antibody did not interfere with the ability of either the cell-free or cell-associated HVT vaccine to provide protection for chickens against challenge from the virulent Marek's disease virus.

Animals↗