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D L Dawe

Publications and source records attributed to D L Dawe.

62 records · Page 4Linked to original sources

Immunization of mice with components of Pasteurella multocida.

Log-phase cells of Pasteurella multocida strain P-1059 were used to prepare isolated culture filtrate, cell wall, and cytoplasmic components. Culture filtrate was further separated by column chromatography. A portion of cytoplasm and culture filtrate was conjugated to ferritin by means of metaxylylene diisocyanate. Cell walls induced more protection in mice than the conjugated or unconjugated cytoplasm or culture filtrate. The cell walls caused edema and erythema when given intradermally in rabbits, whereas cytoplasm and culture filtrate produced dermal necrosis. The first of four chromatographically separated fractions of culture filtrate was possibly more immunogenic in mice than cell walls. This fraction was less reactive intradermally in rabbits than cell walls but more reactive than the other fractions.

Acrylates↗

Antibiotic treatment of ulcerative enteritis of bobwhite quail.

Penicillin-streptomycin, bacitracin methylene disalicylate, zinc bacitracinm, soluble bacitracin methylene disalicylate, streptomycin (25%) and spectinomycin were used as prophylactic and therapeutic treatments for ulcerative enteritis in bobwhite quail (Colinus virginianus). Penicillin-streptomycin was the most effective prophylactic and streptomycin (25%) was the most effective therapeutic agent.

Animals↗

Effect of avian reoviruses on lymphoid organ weights and antibody response in chickens.

Several avian reoviruses were screened to determine their effects on the immune system by inoculating them subcutaneously (SQ) into day-old chicks. For comparison, infectious bursal disease virus (IBDV) was similarly evaluated. The response of the immune system was measured functionally by the hemagglutination-inhibition (HI) response to Newcastle disease virus (NDV) and structurally by changes in the organ-to-body-weight ratios of the bursa of Fabricius, thymus, and spleen. When inoculated SQ, most of the reoviruses caused transient alterations in lymphoid organ weights, decreasing the bursa weight and increasing the spleen weight. Of those reoviruses tested, only one--a commercial vaccine based on the isolate S-1133--demonstrated the ability to interfere significantly with NDV-HI responses, although several had numerically lower titers. Two of the isolates were also evaluated by oral inoculation. Giving the viruses orally did not cause any alterations in organ weights; however, both isolates depressed the HI response of chicks to NDV. Compared with reoviruses, IBDV significantly depressed NDV-HI titers. The structural responses to IBDV differed, however: IBDV significantly depressed bursa weights for all 3 weeks of the test period without affecting spleen weights. Some of the reovirus isolates inoculated SQ were lethal for day-old chicks. This, and their ability to alter the lymphoid-to-body-weight ratios of the spleen and bursa, could be considered valid criteria by which to study the pathogenesis of these agents.

Animals↗

A comparison between the effect of an avian reovirus and infectious bursal disease virus on selected aspects of the immune system of the chicken.

Reovirus 81-176 was inoculated subcutaneously into day-old specific-pathogen-free leghorns and evaluated for its effects on the immune system over a 3-week period. Structural criteria included organ weights of the bursa of Fabricius (BF) and spleen (SP), scoring of histological lesions in the BF, SP, and thymus, and hematological analyses of the circulating leukocytes. Alterations in the functional capacity of the immune system were measured using the graft-versus-host reaction, the response of peripheral blood lymphocytes (PBLs) to mitogens, the ability of circulating monocytes to phagocytize latex beads, and the serological responses to Newcastle disease virus, sheep red blood cells, and Brucella abortus antigens. For comparison, infectious bursal disease virus (IBDV) was similarly evaluated by most of the same tests. Structurally, reovirus 81-176 altered BF and SP organ weights, the total numbers of white blood cells in circulation, and the degree of follicular atrophy in the BF. Functionally, reovirus inoculation reduced both the response of PBLs to the phytohemagglutinin-P stimulation and monocyte uptake of latex beads. According to the protocols used here, no significant alteration in B-cell function could be detected in reovirus-infected chicks. With the exception of leukocyte hematology, IBDV-infected chicks had significantly altered responses in all tests used. By way of comparison, the effects of IBDV were more persistent and pronounced than were those seen with reovirus. The graft-versus-host reaction indicated an elevated and/or uninhibited response of T-cells in the blood of IBDV-infected chicks.

Animals↗