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The effect of feeding the B-cell mitogens Escherichia coli lipopolysaccharide and dextran sulphate on the development of orally induced tolerance to the contact sensitizing agent picryl chloride was studied in mice. Feeding either agent throughout the experiment or during tolerization, increased the tolerizing effect of a single feed of picryl chloride. [ABSTRACT FROM AUTHOR]

The secretory and systemic antibody responses to oral dead Escherichia coli were examined in A strain mice. The best responses were obtained in mice dosed with 1 x 1010 bacteria. Orally immunized animals showed an enhanced response to subsequent parenteral immunization with somatic antigens. This effect could be passively transferred with serum In contrast, the response to the capsular antigen K88 was reduced in the same animals. [ABSTRACT FROM AUTHOR]

The immune response of pigs to oral immunization with dinitrophenylated bovine gamma globulin (DNP-BGG) was assessed using the indirect macrophage migration assay. Two days' exposure to the antigen resulted in the inhibition of macrophage migration by supernatants of cultures from the intestine but not the mesenteric lymph node or spleen. Stimulation for 7 days resulted in macrophage inhibition by supernatants of lymphocyte cultures prepared from the intestine, mesenteric lymph node and spleen. Supernatants of splenic lymphocytes from animals stimulated for 2 or 3 days produced enhancement of macrophage migration. [ABSTRACT FROM AUTHOR]

The immunoglobulin content of porcine nasal, tracheal and bronchio-alveotar secretions was determined. IgA was the predominant immunoglobulin in nasal and tracheal secretions, there being no significant difference (P>0·1) between their IgA:IgG ratios of 2·7:1 and 2·4:1,respectively. In contrast, IgG was the predominant immunoglobulin in bronchioalveolar secretions, the IgA:IgG ratio being 0·7:1. The ability of tracheal and lung tissue to synthesize IgA and IgG was determined in vitro, Tracheal cultures synthesized more IgA than IgG whereas in the lungs the reverse occurred, the ratio of IgA: IgG synthesis being 1·4:1 and 0·4:1, respectively. The proportion of serum-derived IgA and IgG in respiratory tract secretions was determined by measuring the transfer of 125I - and 131I-labelled immunoglobulins from serum. It appeared that more than 97% of the IgA was produced locally. More significantly a proportion of the IgG was also synthesized locally. This proportion was smallest in nasal secretions (21·8%) and greatest in bronchio-alveolar secretions (62·6%). The results suggest that IgG, a large proportion of which is locally synthesized, is important in the homeostatic mechanisms of the lower respiratory tract. [ABSTRACT FROM AUTHOR]

Oral immunization of the lactating sow with live Escherichia coli (O8:K88) stimulated an IgA anti-K88 antibody response in mammary secretions und significantly enhanced the capacity of whey to inhibit adhesion of the inoculum E. coli strain to isolated pig enterocytes. An increase in agglutinating unti-O8 activity was also evident in milk and was associated with both the IgA and IgM immunoglobulin classes. These results are consistent with the concept of a gut mammary link, although measurement of specific antibody in the intestinal secretions of these animals suggested that there may he a difference in response duration at the two secretory sites. Prolonged oral administration of heat-killed organisms also stimulated specific antibody synthesis within the mammary gland, although the response, particularly to the O antigen, was both reduced und delayed in its appearance. [ABSTRACT FROM AUTHOR]

Using a BAB design, a token system requiring cooperative interaction was used to change the reading and vocabulary performance of an 18-member class of third-grade hyperactive boys. Four different colored tokens, which could be exchanged for 15 minutes of play on electrovideo games, were earned by successful completion of two tasks that involved learning to read and to use new vocabulary words in sentences, and two tasks in which the student served as a proctor to a student who had not yet completed those tasks. The mean number of tasks completed during the intervention periods rose to over nine times the number completed during reversal. Additionally, the average completion rate for the school district's standardized weekly reading level examinations rose from four to eight fold during the token conditions. All 18 students responded to the token program by increasing their academic performance.