Search PubMed⌕ Search

Biomedical subjects

J C Edwards

Publications and source records attributed to J C Edwards.

At least 181 records · Page 10Linked to original sources
PubMed1982

The origin of type A synovial lining cells.

Type A synovial lining cells resemble macrophages in their ultrastructure. Type B lining cells, in contrast, resemble tissue fixed synthetic cells such as fibroblasts. Although cells with intermediate features are well recognised, recent evidence suggests that types A and B cells have different origins. Experiments on mouse radiation chimeras suggest a bone marrow derivation for the type A cells, but not for the type B. Esterase activity, surface Ia, and immunoglobulin receptors have been demonstrated in relation to a proportion of lining cells. It seems reasonable at the present time to consider type A lining cells as belonging to the Mononuclear Phagocyte System.

Animals↗
PubMed1982

Demonstration of bone marrow derived cells in synovial lining by means of giant intracellular granules as genetic markers.

Beige mice carry a gene (bg) which codes for the presence of giant intracellular granules in a variety of cell types. Bone marrow from beige mice was transplanted into irradiated normal mice. Giant granules similar to those seen in beige mouse synovial cells were observed subsequently in the synovial lining cells of marrow recipients, indicating an influx of bone marrow derived cells into the synovial lining. Giant granule bearing cells also appeared in the subintima. On electron microscopy giant granules have been demonstrated only in macrophage-like or type A cells in marrow recipient synovia, despite the occurrence of giant granules in both type A and type B lining cells in donor material (beige). This tends to suggest that only the type A lining cells are derived from bone marrow, as might be expected from their similarity to mononuclear phagocytes elsewhere. However, the possibility remains that type B cells are also derived from bone marrow but have a slower rate of replacement.

Animals↗
PubMed1982

Membrane properties and esterase activity of synovial lining cells: further evidence for a mononuclear phagocyte subpopulation.

Recent work in our laboratory with mouse radiation chimeras suggests that the macrophage type of synovial lining cell is derived from bone marrow. Further evidence for including this cell type in he mononuclear phagocyte system is now presented. Rosette formation with IgG coated sheep red cells, immunofluorescent staining for surface Ia antigens, and nonspecific esterase staining all show the presence in the synovial lining of a subpopulation of cells carrying these markers. The proportion of such cells in the lining is very variable, as is the proportion of 'type A' cells recognised with the electron microscope.

Animals↗
PubMed1982

Decomposing potassium peroxychromate produces hydroxyl radical (.OH) that can peroxidize the unsaturated fatty acids of phospholipid dispersions.

The unsaturated fatty acyl residues of egg yolk lecithin are selectively removed when bilayer dispersions of the lipid are exposed to decomposing peroxychromate at pH 7.6 or pH 9.0. Mannitol (50 mM or 100 mM)partially prevents the oxidation of the phospholipid due to decomposing peroxychromate at pH 7.6 and the amount of lipid lost is inversely proportional to the concentration of mannitol. N,N-Dimethyl-p-nitrosoaniline, mixed with the lipid in a molar ratio of 1.3:1, completely prevents the oxidation of lipid due to decomposing peroxychromate at pH 9.0, but some linoleic acid is lost if the incubation is done at pH 7.6. If the concentration of this quench reagent is reduced tenfold, oxidation of linoleic acid by decomposing peroxychromate at pH 9.0 is observed. Hydrogen peroxide is capable of oxidizing the unsaturated fatty acids of lecithin dispersions. Catalase or boiled catalase (2 mg/ml) protects the lipid from oxidation due to decomposing peroxychromate at pH 7.6 to approximately the same extent, but their protective effect is believed to be due to the non-specific removal of .OH. It is concluded that .OH is the species responsible for the lipid oxidation caused by decomposing peroxychromate. This is consistent with the observed bleaching of N,N-dimethyl-p-nitrosoanaline and the formation of a characteristic paramagnetic .OH adduct of the spin trap, 5,5-dimethylpyrroline-1-oxide.

Catalase↗
PubMed1982

Studies on the control of macrophage division during the inflammatory process.

It has been suggested that the regulation of macrophage division may be afforded by the release of soluble mitogenic factors into inflammatory exudate. We have examined for macrophage mitogenic activity in exudates and sera obtained from animals with chronic inflammatory lesions and compared them with fluids from an acute lesions. Both acute and chronic exudates were able to promote DNA synthesis, however acute exudate had higher activity. Although we were able to detect mitogenic activity in the sera obtained from animals with acute pleurisy, we were unable to detect any activity greater than control in sera obtained from animals with chronic inflammatory lesions. We propose the presence of mitogenic factors for macrophages in both animals with acute and chronic lesions may help to explain the increasing predominance of mononuclear cells seen during the progression of acute to chronic inflammation.

Animals↗
PubMed1981

The formation of a structure with the features of synovial lining by subcutaneous injection of air: an in vivo tissue culture system.

We have attempted to verify the suggestion that synovial membrane is the result of mechanical disruption of connective tissue, and may occur at any site. Mechanical disruption of the subcutaneous connective tissue was achieved in rats and mice by the repeated injection of air. The resulting cavities developed a lining structure with many of the features of synovial membrane as judged by electron microscopy, and light microscopy using haematoxylin and eosin and van Gieson stains, esterase activity and immunofluorescent staining for Ia antigen. A structure closely resembling synovium is formed as early as 6 days, providing a convenient method for studying large quantities of facsimile synovial tissue under a wide variety of easily administered stimuli.

Air↗
PubMed1981

A clinical and echocardiographic study of patients with the hypermobility syndrome.

Three age- and symptom-matched groups of patients with a hypermobility score of 5-9, 3-4, and 0-2 (controls), respectively, were examined for clinical and echocardiographic evidence of mitral valve prolapse and other stigmata of a collagen disorder. Mitral valve prolapse, a reduced upper segment/lower segment mitral ratio, reduced skin thickness, spinal anomalies, and a history of fracture were found to be significantly commoner among the hypermobile patients than the controls. The data suggest that the so-called hypermobility syndrome, far from being a benign locomotor disorder of healthy persons, may be a forme fruste of a hereditary disorder of connective tissue.

Adult↗
PubMed1980

Corrective cardiac surgery in infants. A review of 136 patients including the contribution of postoperative ventilation.

This is a review of 136 patients who have undergone corrective surgery for congenital heart disease with the aid of profound hypothermia in a 6-year period. Almost all patients were less than one year old and less than 10 kg. In 1979 the average age was 3.4 months and the average weight was 4.1 kg in 34 infants. The hypothermic technique consisted of surface cooling followed by cardiopulmonary bypass cooling and circulatory arrest during definitive surgery. The hospital mortality was 26% for the whole period, having decreased from 53% in 1974 to 15% in 1979. After operation 70% of patients with uncomplicated ventricular septal defect or the tetralogy of Fallot were extubated within 4 hours, 65% of all patients were extubated within 12 hours of operation.

Anesthesia, General↗
PubMed1980

Relationship between pressure and digital vasculitis in rheumatoid disease.

The sites of 92 rheumatoid nailfold lesions were compared with sites of pressure as indicated by tissue blanching during gripping. A close correspondence between sites of blanching and sites of vasculitis was found, and this is discussed in relation to the possible role of vascular compression and blood stasis in the development of rheumatoid vasculitis.

Arthritis, Rheumatoid↗