Robert Stinson

Light and electron microscope structure of secretory cells in the medulla of bursal follicles of normal and cyclophosphamide treated chickens.

Abstract A specialized cell was identified in the medulla of bursal follicles referred to as a secretory cell (SC). The SC, present at all ages was concentrated in the vicinity of the corticomedullary border. Each secretory cell near the nucleus usually possessed a single long process containing 3–10 dark granules surrounded by a membrane. The SC increased in number and apparent secretory activity after cyclophosphamide treatment. All medullary pores were filled with a darkly staining substance, apparently secreted by the SC.

A biphasic graft vs host response in aging chickens

Abstract The graft vs host (GvH) and phytohemagglutinin (PHA) wattle responses were the parameters chosen to evaluate cell-mediated immunity in aging chickens. At 6 and 24 months of age female spleen cells were significantly more effective in eliciting a GvH response than spleen cells from 1-, 2-, 12-, and 18-month-old females. The biphasic GvH response produced by female spleen cells was not observed for male spleens. On the other hand, peripheral blood lymphocytes from both males and females exhibited a single peak, 3–6 months, in their ability to produce a GvH response. The thymic-dependent PHA wattle response of males was significantly greatest at 1 month of age and declined thereafter. Once again the females exhibited a different pattern than the males. At 1 month of age the females wattle response was significantly greater than at 3 months, but rather than declining with age the wattles of aging females responded like 1-month-old females. Several mechanisms are offered to explain the apparent age-related regression-regeneration of cell-mediated immunity in the female.

Immunoglobulin-positive cells from the gland of harder and bone marrow of the chicken

Abstract Cells were collected from the gland of Harder (GH) and bone marrow (BM) of 14-, 21- and 32-week-old birds and were incubated with an 125 I-labeled rabbit anti-chicken Ig (IgG and IgM) serum. At 14 weeks of age the percentage of Ig + small lymphocytes (SL) in the GH and BM was similar. However, by 21 weeks of age Ig + SL in BM had increased to approximately 19% of total lymphocytes while the Ig + SL in the GH represented less than 1.7% of the lymphocyte pool. A marked drop in the number of Ig + SL in BM occurred by 32 weeks of age. These data suggest that either the BM may be dependent on the bursa for maintenance of its Ig + SL or it is unable to produce in situ or maintain Ig + SL with age. In the GH the predominant cell was the plasma cell (PC). Labeled PC (> 20 grains) exceeded 80% of the total PC pool in the GH. These data contrast with the apparent deficiency of Ig receptors on murine PC. The maintenance of a large number of PC in the GH without the presence of Ig + SL illustrates the uniqueness of this gland.

An electron and light microscope study of the caecal tonsil: The basic unit of the caecal tonsil

Abstract The caecal tonsil (CT) develops in the initial 4–18 mm of each of the chickens caecal pouches. Utilizing scanning and transmission electron microscopy and light microscopy we identified the basic unit of the CT. The basic unit contains a central crypt with several primary branches, dense lymphoid tissue and germinal centers. The main structural design of the CT appears to correspond to the mammalian palatine and lingual tonsils.

Scanning electron microscopy of chicken lymphocytes: A comparative study of thymic, bursal, and splenic lymphocytes

Abstract Using scanning electron microscopy (SEM), human and murine lymphocytes have been divided into 2 morphological cell populations based on their surface morphology (i.e. T cells are smooth and B cells were rough). This classification system is, however, controversial, and not all investigators feel this is a valid criteria for delineating T and B cells. The chicken provides an ideal system to study this problem with its compartmentalization of T and B cells in the thymus and bursa of Fabricius, respectively. The splenic, bursal, and thymic lymphocytes of 2–9 week old chickens were examined by SEM and scored as either rough (villous), intermediate, or smooth based on the number of surface projections present. We observed the smooth type to be most prominent regardless of the source of the cell ( > 90%), even in the spleen which showed the greatest diversity. SEM, therefore, cannot be used as a tool to distinguish between T and B cell populations in the chicken.

Antibody reactivation of Kepone inhibited brain ATPase activities

Abstract 1. 1. Kelevan (a derivative of Kepone) was covalently bound to BSA (BSA-Kel) through a succinimide derivative, and rabbits were immunized by injection of the hapten-protein conjugate in an emulsion of Freunds complete adjuvant. 2. 2. Immunoglobulin fractions (Ig) were prepared from control and immune rabbit serum and Ig from BSA-Kel antiserum produced a complete reversal of Kepone inhibition of dog brain ATPase activities under given experimental conditions. 3. 3. These results indicate that in studies with the chlorinated hydrocarbon pesticides (Kepone and DCPD) care must be taken during tissue preparation to minimize possible reversal of ATPase inhibition.

Properties of an antibody to Kelevan isolated by affinity chromatography: Antibody reactivation of ATPase activities inhibited by pesticides☆

Abstract Antibody molecules were produced by injection of BSA-Kelevan into chickens and rabbits. Pure antibody was obtained by a single pass of blood serum through an affinity column. The affinity gel was prepared by covalently binding BGG-Kelevan to activated Sepharose 4B-CN. Purity of the antibody was determined by ultracentrifugation and gel electrophoresis. Properties of the antibody included: sedimentation coefficient = 6.2, pI = 7.0, calculated MW = 150,000, and precipitin band formation using the microouchterlony test. The antibodies in free or immobilized form were able to prevent or reverse Kepone inhibition of ATPase activity from a variety of tissues from different sources. About 70 μg (approx 0.4 μM) of purified antibody was sufficient to restore the activity of mitochondrial (oligomycin-sensitive) Mg2+ ATPase activity which had been inhibited (in vitro) by 1 μM Kepone. The antibody was effective in preventing enzyme inhibition by other organochlorine pesticides with widely differing molecular structures. However, nonchlorinated inhibitors of mitochondrial oligomycin-sensitive Mg2+ ATPase activity were much less affected by the antibody. The available evidence suggests that the antibody binding site for the hapten may be specific for secondary or induced bonding forces due to the carbon-chlorine bonds rather than for a specific molecular structure.