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Biomedical subjects

M D Armstrong

Publications and source records attributed to M D Armstrong.

At least 19 recordsLinked to original sources

Immune-endocrine interactions of the hypothalamus-pituitary-thyroid axis: integration, communication and homeostasis.

The immune and neuroendocrine systems are two essential physiological components of mammalian organisms. Although each is primarily committed to a set of tasks involved, on the one hand, in the protection from infection and disease, and on the other hand, in the regulation of metabolism and other physiological activities, there is also evidence indicating that active and dynamic collaborations exist between those systems in the execution of their designated functions. These interactions occur at many stages of embryonic and neonatal development, and they are a continual part of the normal homeostatic balance needed to maintain health. The present review discusses various historical and contemporary perspectives of immune-endocrine interactions involving the hypothalamus-pituitary-thyroid axis, and offers a hypothesis of how this aspect of the neuroendocrine system participates directly in the immune response to antigenic challenge, infection and disease.

Animals↗

Differential expression of CD43 isoforms on murine T cells and their relationship to acute intestinal graft versus host disease: studies using enhanced-green fluorescent protein transgenic mice.

Three mAb (R2/60, S7 and 1B11) were used to study the expression of murine CD43 on peripheral T cells and intestinal intraepithelial lymphocytes (IEL) from normal mice, and from mice during acute graft versus host disease (GVHD). In the spleen, essentially all T cells expressed the R2/60 and S7 antigens, whereas the 1B11 antigen was expressed on about half of the CD8(+) cells and approximately 15% of CD4(+) T cells. Interestingly, a significant proportion of resting splenic B cells expressed the 1B11 and R2/60 antigens, but not the S7 antigen. The majority of IEL expressed R2/60 antigen; however, the S7 and 1B11 markers were differentially expressed on CD8alpha, CD8beta, TCRalphabeta and TCRgammadelta cells. Immunoprecipitation and Western blotting analyses identified characteristic 115 and 130 kDa reactive components from IEL lysates with mAb S7 and 1B11 respectively, and reactivity to both molecular entities by mAb R2/60. During acute intestinal GVHD induced by injecting CB6F(1) athymic nude mice with spleen cells from C57BL/6 enhanced-green fluorescent protein transgenic mice, 80-90% of donor T cells in the intestine epithelium expressed all CD43 isoforms; however, the level of expression of the 130 kDa CD43 antigen increased significantly and the level of the 115 kDa antigen decreased on GVHD donor T cells compared to cells at the time of transfer. Using EL4 cells, a similar shift in the expression of CD43 isoforms occurred experimentally following treatment with neuraminidase, suggesting that the type of CD43 isoform expressed on T cells is strongly influenced by conditions which affect membrane charge. The significance of these findings for intestinal immunopathology is discussed.

Animals↗

N-delta-acetylornithine and S-methylcysteine in blood plasma.

N-delta-Acetylornithine and S-methylcysteine have been identified as minor components of deproteinized blood plasma of human and bovine blood. Human blood plasma contains a variable amount of acetylornithine, averaging 1.1 +/- 0.4 mumol/l (range 0.8--0.2 mumol/l). Urine contains a very small amount of acetylornithine, approximately 1 nmol/mg creatinine (1 mumol/day). Human blood plasma contains 3.9 +/- 1.9 mumol/l (range 1.4--6.5 mumol/l) of S-methylcysteine. Urine contains approximately 5 nmol/mg creatinine; after acid hydrolysis the amount is increased to 20 nmol/mg creatinine.

Animals↗

The occurrence of cystinylglycine in blood plasma.

Cystinylglycine has been identified as a minor ninhydrin-positive component of deproteinized blood plasma from human, bovine, rat and rabbit blood. The amount present in human blood plasma is approximately one-fifth of that of cystine and is not significantly correlated with age or with the cystine level.

Adolescent↗