PubMed · 4684908
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1973. Tympanic transplants.. https://pubmed.ncbi.nlm.nih.gov/4684908/
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We studied the presence of Natural antibodies in plasma samples from individual birds from selected chicken lines at young and old age. Binding, specificity, and relative affinity to various antigens were determined in plasma from non-immunized female chickens at 5 weeks of age, and in plasma obtained from the same chickens one year later using indirect two-step ELISA. Birds were from three different lines. The lines were divergently selected for either high (H line) or low (L line) antibody titers to Sheep Red Blood Cells at 5 weeks of age, next to a random bred control (C line). Binding of plasma immunoglobulins (Ig) from all three lines was found with chicken-egg-white protein (CEP), ovalbumin (OVA), myoglobin (MYO), thyroglobulin (THYRO), keyhole limpet hemocyanin (KLH), bovine serum albumin (BSA), and transferrin (TRANS). Significantly higher binding to most antigens was found with plasma Ig from adult birds from the H line as compared to plasma Ig from the L line, whereas binding of plasma Ig from C-line birds was in between or similar to the H or L line, respectively. Binding of Ig to all antigens in all three lines was significantly higher in plasma obtained at one year of age as compared to plasma obtained at 5 weeks of age. A competitive ELISA with homologous and heterologous antigens was used for determining specificity of the antigen-binding antibodies. Nai;ve plasma samples were characterized by a broad binding to all antigens tested. Inhibition of binding to specific antigens was possible with a broad range of heterologous antigens, but highest competition of binding was obtained with homologous antigen. Both linear regression analysis of serial dilutions of the plasma Ig binding the antigens, as well as competitive ELISA with homologous antigen indicated that plasma Ig from the H line and plasma Ig from the L line had similar affinity characteristics to the antigens tested with the exception of OVA and KLH. Pooled non-immune plasma from H line birds bound to CEP, OVA, THYRO, TRANS, MYO, KLH, and salt-precipitated extracts and supernatants of extracts from chicken heart, spleen, liver, brain, bursa, thymus, and kidney, respectively, as determined by Western blotting. The increasing presence of antibodies in nai;ve chicken plasma binding heterologous and homologous (tissue) antigens indicates the presence of Natural antibodies in poultry. Apart from age, increasing levels of Natural antibodies may be related with the genetically based magnitude of specific antibody levels in the chicken lines studied.
Parabiosis during pregnancy regularly results in an exchange of hematopoietic stem cells between cattle twins. We have exploited this phenomenon and show differences in the levels of chimerism between the descendant cell types. Female recipients were screened for the levels of male donor contribution in surface IgM-bearing B lymphocytes versus CD3(+) T lymphocytes using immunomagnetic fractionation and Y-chromosome specific in situ hybridization. Two calves of 15 were discovered to have less than 10% of B cells but over 70% of T cells and other blood leukocytes of male origin. The donor cell ratios remained stable for 9 months. Analysis of lymphoid tissues revealed a similar cell type specific pattern of male cell ratios in both female calves and one twin brother. These findings are in agreement with the existence of an essentially self-sufficient population of developing B cells that gives rise to the peripheral pool of B lymphocytes in young cattle.
We present a new growth test data analysis for toxicity tests with the midge Chironomus riparius. The analysis is based on mathematical models which proved to be able to predict growth and emergence of non-exposed organisms for diverse feeding levels or densities. Here, we adapt these models to account for toxicity. We distinguish between two modes of action of the compounds: decrease of feeding or increase of growth energy costs. The models are used to analyse growth data with organisms exposed to copper spiked artificial sediments. Both models provide a good fitting of the data in the case of feeding ad libitum, but only the growth costs model can account for effects of copper in the case of food limitation. We also show that the threshold of effects do not depend on the age (the no effect concentrations (NOEC) are 6, 7 and 9 mg/kg, respectively, for second, third and fourth instars larvae), but that, as soon as this threshold is exceeded, fourth instar larvae are less affected by copper than earlier larvae. Our models constitute a step towards a more biologically relevant analysis of standardized tests, which should facilitate both the understanding of the mechanisms of toxicity and the change of scale from the individual to the population.