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Biomedical subjects

F L Pearce

Publications and source records attributed to F L Pearce.

At least 163 records · Page 9Linked to original sources
PubMed1977

Immunogenic contaminants in mouse nerve-growth factor.

Experiments are described that confirm the presence of gamma-globulin in standard preparations of mouse nerve growth factor (7-S complex and beta subunit) and show that antibodies to this protein are present in horse antisera to the growth factor. These antibodies may be partially removed by adsorption with soluble antigen and totally removed by affinity chromatography on columns of insolubilised antigen. These procedures do not affect the potency of the antiserum in vitro or in vivo. Contaminating globulin may be removed from samples of the isolated beta subunit by gel filtration to give an immunochemically pure preparation which will permit more meaningful studies on nerve growth factor and its antiserum.

Animals↗
PubMed1977

Isolation and study of functional mast cells from lung and mesentery of the guinea pig.

A method is described for the dissociation of guinea pig lung and mesentery into their component cells. The method comprises incubation of the tissues with the enzyme pronase in Ca++- and Mg++-free saline followed by mechanical dispersion and yields on average 3-8% free mast cells. These cells are morphologically intact and viable. They retain an active sensitization or can be passively sensitized. The levels of cAMP and cGMP in the whole cell suspension respond to catecholamine, histamine or cholinergic stimulation in a way similar to that observed in the corresponding undispersed tissue. Although the separation of guinea pig mast cells from other cells proved to be more difficult than the purification of rat mast cells, an inrichment of greater than 50% has been achieved. The mast cells isolated by this method proliferate in vitro and have been cultured successfully for several months.

Anaphylaxis↗
PubMed1977

The use of porous plastic filters in the preparation of cell suspensions.

Suspensions of cells were prepared by dissociation of various tissues with the proteolytic enzyme pronase. Debris, undisrupted tissue and cell clumps were effectively removed from the suspensions by passage through VYON F porous plastic filters whereas isolated cells were recovered without significant losses. The viability of the cells, as judged by dye exclusion and subsequent behavior in tissue culture, was not affected by the treatment.

Animals↗
PubMed1976

Immunological properties of nerve growth factors.

Antisera were raised against nerve growth factors isolated from mouse salivary gland and five venoms representative of the three main families of poisonous snakes. Immunochemical cross-reactivity was assessed from the ability of the antisera to inhibit the biological activities of the heterologous antigens. The high and low molecular weight forms of the salivary gland factors were found to be immunologically identical but distinct from the snake venom factors. The snake venom factors, on the other hand, were immunologically closely related to each other but not identical.

Animals↗
PubMedDate not supplied

Mast cell heterogeneity in man: unique functional properties of skin mast cells in response to a range of polycationic stimuli.

Human mast cell heterogeneity was assessed by histochemical and detailed functional criteria using mast cells isolated from foreskin, uterine myometrium and lung parenchyma. The skin mast cells were histochemically distinct from their counterparts in the other two tissues by being predominantly insensitive to blockage of dye-binding following formalin fixation (ca. 80%). Functionally, a wide range of structurally diverse polycationic compounds induced selective histamine release from the skin mast cells (ca. 10% at top concentrations) although these cells were less responsive to immunological ligands and calcium ionophores when compared with the uterine and lung cells. The basic compounds, polyarginine and histone, proved to be more generalised histamine liberators as compared with their structural analogues, polylysine and protamine sulphate, probably by virtue of their high content of arginine residues and hydrophobic nature (histone). Studies with the anaphylatoxin, C3a, and its analogues 21R and C3ades Arg on skin mast cells emphasized the importance of basic amino acids for histamine-liberating peptides. Skin mast cells also proved more susceptible than their uterine counterparts to lysis by the detergents, Triton X-100 and Tween 20, suggesting that fundamental differences in membrane structure and/or fluidity might account for functional heterogeneity within the human mast cell population.

Amino Acids↗