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P Chien

Publications and source records attributed to P Chien.

42 records · Page 3Linked to original sources
PubMed1985

Differential interleukin-1 elaboration by density-defined human monocyte subpopulations.

Interleukin-1 (IL-1) is an important immunoregulatory peptide produced by monocytes and macrophages. Because mononuclear phagocytes are morphologically and functionally heterogeneous, we examined whether they differ in their ability to elaborate IL-1. We used discontinuous Percoll gradients to obtain five density-defined human blood monocyte subpopulations. Unfractionated monocytes and their subsets were compared for their ability to stimulate thymocyte proliferation. Supernatants obtained from the denser monocytes consistently contained more IL-1 activity than did supernatants from the less dense cells. This difference in IL-1 activity was the result of differences in IL-1 elaboration, not the selective production of an inhibitor of IL-1-induced thymocyte proliferation. These data demonstrate that density-defined human monocyte subpopulations differ in their capacity to elaborate IL-1.

Cell Division↗
PubMed1985

Differential interleukin 1 elaboration by unfractionated and density fractionated human alveolar macrophages and blood monocytes: relationship to cell maturity.

The elaboration of interleukin 1 (IL 1) by mononuclear phagocytes is important in the regulation of human inflammatory and fibrotic reactions. Mononuclear phagocytes are morphologically and functionally heterogeneous cells. To further understand the processes controlling inflammation and fibrosis, in particular that in the human lung, we studied the elaboration of IL 1 by unfractionated and density-fractionated human alveolar macrophages and blood monocytes. Stimulated blood monocytes elaborated more IL 1 than stimulated alveolar macrophages. In addition, denser alveolar macrophages and blood monocytes elaborated more IL 1 than less dense alveolar macrophages and monocytes. Lastly, as monocytes matured in vitro, they lost their ability to elaborate IL 1 and became less dense. Thus, there is variability between and within mononuclear phagocyte cell populations in their ability to elaborate IL 1. These differences may result in part from differences in cell maturation.

Cell Differentiation↗
PubMed1983

Isolation of cultured human monocytes/macrophages in suspension utilizing liquid and solid phase gelatin.

We developed a method which provides a mechanism for isolating adherent mononuclear cells without subjecting them to traumatic physical or chemical methods of removal from their surface attachment sites. This method uses gelatin, which is solid at room temperature and liquid at 37 degrees C, as the adhering surface. Blood monocytes bind to gelatin-coated flasks at room temperature and are easily and gently removed when the gelatin is liquified at 37 degrees C. Monocytes, so isolated, are viable and functional [phagocytosis, adherence and Fc(IgG) and C3 receptor activity].

Cell Adhesion↗
PubMed1975

Ultrastructure of nerve plexus in flatworms. II. Sites of synaptic interactions.

Synaptic components from the peripheral nervous system of the polyclad flatworm. Notoplana acticola, are described from electron microscopic observations. Quasi-neuropile, defined as clusters of neurites containing synaptic vesicles, occurs as scattered islands among the peripheral nerve cords of the plexus. Some neurite clusters only contain one type of synaptic vesicle but others are mixed. The most usual synaptic configuration consists of a single presynaptic element and a pair of postsynaptic neurites sharing a common synaptic cleft. These synapses are polarized and contain clear, 420 A vesicles. GABA-type synapses are also found. At least two kinds of solid-core vesicles also occur.

Animals↗