The function of Ia+ dendritic cells and Ia- dendritic cell precursors in thymocyte mitogenesis to lectin and lectin plus interleukin 1.

The response of thymocytes to lectin is a standard tissue culture model for identifying cytokines such as IL-1 that are required for thymocyte mitogenesis. To study accessory cell requirements for these responses, it was necessary to deplete endogenous accessory cells with two techniques: anti-Ia and complement, and passage over nylon wool. Proliferation to Con A was then restored with 0.

Ontogeny of 'macrophage' function. VI. Down-regulation for Ia-expression of newborn mouse macrophages by endogenous beta-interferon.

Peritoneal exudate macrophages (M phi) of newborn mice (NB-M phi) were apparently almost incapable of expressing Ia antigen even if stimulated by IFN-gamma. No significant difference was observed in the number and the affinity of receptors for IFN-gamma between NB-M phi and M phi of adult mice (Ad-M phi). Addition of indomethacin, a prostaglandin synthesis inhibitor, was ineffective in enhancing the Ia-expression of NB-M phi.

Immortalization of murine leukocytes by oncogenes. II. Phenotypic characterization of transformants immortalized by v-src or Ha-ras oncogenes: expression of B220, a B-cell lineage specific antigen.

In the course of study to obtain murine dendritic cell lines using oncogenic retroviruses, we have established several immortalized cell lines with characteristics different from those of dendritic cells. The transformants were mainly round nonadherent cells, capable of growing in soft agar, and negative for nonspecific esterase activity. Profiles of cell surface antigens were examined by indirect immunofluorescence technique.

Activity of motor units during concentric and eccentric contractions.

Motor unit activity was investigated in the biceps brachii of twelve men during concentric (CC) and eccentric (EC) contractions by means of computer aided intramuscular spike amplitude-frequency (ISAF) histograms and surface EMG frequency power spectral analyses. Simultaneous recordings of the intramuscular and surface EMG signals were made during both types of contractions with the elbow joint angle varying from 30 to 150 degrees in reference to a fully extended position. Results demonstrated that r.

Accessory cell functions of dendritic cells and macrophages in the thymic T-cell response to Con A.

Accessory cell (A cell) functions of splenic dendritic cells (DC) and peritoneal macrophages (M phi) were investigated in the Con A-stimulated proliferative response of thymic T cells. DC were more efficient as A cells than M phi in respect of their necessary cell numbers, Con A dose and culture period required for optimal response. Con A-pulsed T cells proliferated with the aid of lymphocyte activating factor(s) (LAF) derived from M phi, even in the apparent absence of A cells.

Role of macrophages as modulators but not as autonomous accessory cells in the proliferative response of immune T cells to soluble antigen.

The role of murine macrophages (M phi) and that of splenic dendritic cells (DC) were investigated in the antigen-specific proliferative response of memory T cells of mice primed with key-hole limpet hemocyanin (KLH) 6 weeks or more before. Peritoneal M phi, whether expressing Ia antigens or not, did not function as autonomous accessory cells (A cells). A-cell activity of the spleen adherent cell population, which comprised M phi in the majority and DC in the minority, was abolished by eliminating DC with a DC-specific monoclonal antibody and complement, and regained by the addition of a small number of DC.

Developmental fall in whole body protein turnover of chick embryos during incubation.

Whole body protein turnover was measured in chick embryos during incubation to investigate whether or not there is a fall in fractional rates of protein synthesis and degradation during development. Stable isotopically labelled [15N]phenylalanine was injected intraperitoneally into embryos on days 12 and 19. From 60 to 90 min after injection the isotope enrichment in free and protein-bound phenylalanine was measured with a selected-ion gas-chromatograph mass-spectrometer.

Development of a selective clean-up method using immobilized antibody and its application to HPLC and GC/MS determination of a carbacyclin derivative, CS-570, in plasma.

Methods for the determination of CS-570, a chemically stable prostacyclin analogue, in plasma were developed by using an immobilized antibody column followed by fluorescence HPLC and GC/MS. The CS-570 antibody, obtained from rabbit plasma by giving CS-570-BSA for a few months, was coupled to Sepharose 4B and used as extraction phase for sample clean-up and extraction of the drug. A plasma sample was applied to this column, washed with water and the drug was eluted with 90% acetonitrile.