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Biomedical subjects

D L Dawe

Publications and source records attributed to D L Dawe.

At least 55 records · Page 3Linked to original sources

A transient deficit in neutrophilic chemotaxis in a dog with recurrent staphylococcal pyoderma.

A transient neutrophilic chemotactic deficit was confirmed in a 3 1/2-year-old castrated male dog with recurrent staphylococcal pyoderma accompanied by a persistent eosinophilia and intermittent basophilia. Neutrophilic chemotaxis was quantitatively assessed over the next seven months, and the disappearance of the chemotactic deficit correlated with complete clinical remission of the skin lesions. Aberrations of the complement system were not discovered, and the dog's serum showed increased chemoattractiveness for control neutrophil preparations.

Animals↗

Polymyositis in dogs.

Polymyositis was diagnosed in nine dogs. Factors utilized in making the diagnosis included (1) muscle pain or weakness, (2) high concentrations of serum muscle enzymes, (3) electromyographic abnormalities, and (4) histopathologic evidence of muscle necrosis and inflammation. Clinical signs included muscle pain, weakness, stilted gait, and pyrexia. Serum muscle enzyme concentrations were high in only three dogs. There was no apparent correlation between enzyme concentrations and severity of clinical involvement or degree of muscle necrosis on biopsy. Electromyographic changes included polyphasic motor unit potentials, fibrillation potentials, and positive waves. Variable degrees of muscle regeneration, degeneration, and inflammation were seen. Prednisone (2.2 mg/kg, OD, per os) was used effectively to treat four dogs. One dog improved initially but was euthanatized later when clinical signs became more pronounced. Three other dogs developed aspiration pneumonia secondary to megaesophagus and either died or were euthanatized.

Animals↗

Experimentally induced Leptospira interrogans serovar autumnalis infections in young swine.

Leptospira interrogans serovar autumnalis strain 621 was proven to be infective for swine by intranasal and ocular inoculation and by contact exposure. The course of the disease was that of a chronic asymptomatic infection. Throughout the experiment, leptospires were observed in all tissues examined by darkfield microscopy of 10% tissue suspensions and examination by indirect fluorescent antibody technique of frozen tissue sections. Infected pigs had increasing antibody titers, as determined by the microscopic agglutination test. The organism spread from intranasally inoculated pigs to contact controls.

Administration, Intranasal↗

Specific antigens of chicken thymus.

Purified plasma membranes from chicken thymus and bursa cells were prepared and solubilized with sarkosyl (sodium salt of N-methyl-N-(1-oxodecyl)-glycine). Antisera to solubilized thymus plasma membrane (TPM) were produced in rabbits and the globulin fraction obtained by ammonium sulfate precipitation. Four precipitating antigens were detected in solubilized TPM by immunoelectrophoresis. Following absorption with chicken serum and bursa plasma membrane (BPM) immunosorbents, three antigens, designated T1, T2, T3, were specific for the TPM fraction, and one antigen, T1, was found in soluble extracts of thymus tissue. Absorption with isolated plasma membrane and whole cells indicated that the T1 and T2 antigens in solubilized TPM are associated with the plasma membrane but not expressed on the surface of the cell. A common antigen, designated BT, was detected in BPM and TPM fractions and in membrane preparations of spleen. The antigens were not detected in any other tissues or cells including brain, circulating lymphocytes and erythrocytes.

Animals↗

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↗

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↗

Immune response of channel catfish under different environmental conditions.

Channel catfish were maintained under conditions of low (15.4 C) and fluctuating (15.4 to 26.9 C/24 hours) temperatures, low (126 mg/L NO3-N) and high (289 mg/L NO3-N) nitrate in recirculating systems, crowding (171 g body mass/L), and fasting. They were vaccinated with formalin-killed enteric red-mouth bacterium, and antibody titers were monitored weekly for 10 weeks. Only those fish maintained in low or fluctuating temperature environments had significant (P less than 0.01) immunosuppression. The other environmental conditions studies, which are commonly encountered in intensive fish culture operations, did not compromise the humoral immune response of channel catfish.

Animals↗

Fowl cholera immunization in turkeys. I. Efficacy of various cell fractions of Pasteurella multocida as vaccines.

Cell fractions of Pastuerella multocida (P-1059) were tested as vaccines against fowl cholera in turkeys. These fractions were culture filtrate, cell wall, and cytoplasm. A second culture filtrate preparation made from cells grown on blood-agar rather than the standard medium was also tested along with a "combination" preparation made by recombination of the cell fractions. Each preparation was tested in three vehicles: saline, alum (0.5%), and Freund Incomplete Adjuvant (50%). The turkeys vaccinated with these preparations were challenged by exposure to an experimental epornitic of fowl cholera. The combination fraction appeared to be the most promising vaccine when compared to the protective action of the commercial bacterin included in the test as a positive control.

Agar↗

Fowl cholera immunization in turkeys. II. Use of experimental epornitic method to study vaccine efficacy in flocks of turkeys.

Groups of turkeys were challenged with Pasteurella multocida (P-1059) by the contact method. In this method, turkeys are artificially infected by the intramuscular injection of P. multocida organisms and are then introduced into the test group. The death patterns resulting from this contact method of challenge are either normally distributed or skewed to the right.

Animals↗

Fowl cholera immunization in turkeys. 3. Significance of market quality in the evaluation of fowl cholera vaccines.

Turkeys vaccinated with various experimental vaccines and a commerical bacterin for fowl cholera and surviving an artificially induced epornitic were killed, and their carcasses were examined for wholesomeness. It was evident that, if the "fitness for human consumption" judgement was considered in addition to mortality, efficacy ratings of the various vaccines changed. This suggests that the "fitness for human consumption" factor be considered in future evaluation of biologicals for use in meat-producing birds.

Agar↗