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Biomedical subjects

O J Fletcher

Publications and source records attributed to O J Fletcher.

At least 37 records · Page 2Linked to original sources
PubMed1980

Ring-stabilization technique for collection of avian air sacs.

Histologic features of chicken air-sac membranes harvested with rings were compared with those of membranes collected on cards. Ring stabilization of the tissues throughout fixation, dehydration, and embedment was found to reduce markedly the artifacts and the loss of normal tissue architecture observed within the wall of card-collected air sacs.

Air Sacs↗
PubMed1978

Comparative study of experimental inclusion body hepatitis of chickens caused by two serotypes of avian adenovirus.

Twenty 1-day-old specific-pathogen-free chickens each were given an intraabdominal inoculation of either a type-8 avian adenovirus, [AMG 5 (2a], or a type-5 avian adenovirus, inclusion body hepatitis virus (IBHV). The diseases produced were similar. High (60-100%) mortality and statistically significant depression of body weights occurred in both infections. There were necrotizing hepatitis and pancreatitis, lymphoid depletion in the spleen, bursa of Fabricius and thymus, hydropericardium, nephritis and enteritis. Intranuclear inclusions occurred in affected organs. Fluorescent-antibody staining, the Feulgen reaction for deoxyribonucleic acid and electron microscopic studies, as well as studies from the literature, indicated that basophilic inclusions consisted of assembled adenovirions.

Adenoviridae Infections↗
PubMed1977

In vivo function tests of the effect of tilorone and niridazole on cell-mediated immunity in chickens.

The need for effective, safe, specific cellular immune suppression in avian research led to the study of effects of tilorone and niridazole on cell-mediated immunity of chickens. Two in vivo tests for cell-mediated immunity function were used--the graft-vs-host (GvH) test and the delayed hypersensitivity (DH) test. Humoral immunity was evaluated by measuring natural hemagglutination (HA) titers against rabbit red blood cells. Intraperitoneal administration of tilorone to young chickens appeared to have severe toxic side effects and was of little value as an immune suppressant. Oral administration of tilorone to 6-week-old chickens caused DH suppression, but no marked effect was seen on GvH reactions or HA titers. Toxicosis appeared less severe. Oral administration of niridazole to 6-week-old birds caused nearly complete loss of GvH and DH reactivity but caused an increase in HA titers. General toxic effects of niridazole were not apparent.

Animals↗
PubMed1977

Dose response, prevention, and treatment of a transplantable lymphoid tumor.

Transplantable lymphoid tumor (TLT) cells in doses ranging from 10(2.43) to 10(6.80) were transplanted into 3-week-old chicks. A total of 199 chicks in 31 dosage groups was included in this 2-year study. Overall mortality was nearly 100% and analysis of the results revealed no significant differences in mortality among the groups. A significant (P less than 0.001) linear relationship existed between log10 of the TLT cell dose and mean survival time. Serum obtained from chickens which survived TLT growth, regression, and challenge inoculation was administered to chicks 4, 7, or 11 days before TLT induction. Of the chickens in each of these 3 groups, 80 to 100% survived compared with 0 to 20% in those given control serum. In chicks with actively growing TLT that were treated with 2 injections of plasma from TLT-resistant chickens, mean survival time was lengthened and survival was increased by 36%. Lymphocytes from resistant chickens or plasma od and survival was increased by 36%. Lymphocytes from resistant chickens or plasma or lymphocytes from control chickens did not affect survival time or percentage of survival. In the present study, results demonstrated a similarity to the TLT model studied 30 years ago and established the usefulness of this model in the study of serum immunotherapy.

Animals↗
PubMed1976

Histology of air sac lesions induced in chickens by contact exposure to Mycoplasma synoviae.

Chickens were housed when 1 day old with chickens experimentally infected with Mycoplasma synoviae. Air sacs from 16 of the 2-week-old and eight of the 3-week-old contact-exposed chickens were given gross lesion scores and embedded in glycol methacrylate for slide preparation. Histologic lesions in air sacs with gross scores of 0-2 were mild edema resulting in a two to eightfold increase in air sac thickness, capillary proliferation, and exudate consisting largely of heterophils and necrotic debris. Histologic lesions in air sacs with gross scores of 3 and 4 were marked hyperplasia of epithelial cells and diffuse infiltration of the air sac connective tissue by mononuclear cells. Nine of 10 air sacs with gross scores of 0 had no histologic evidence of inflammation. The most severe histologic lesions were in those air sacs with gross scores of 4. The glycol methacrylate procedure resulted in 2-mum sections with excellent cellular detail.

Air Sacs↗