Biomedical subjects
Publications and source records attributed to C O'Leary.
A 28 year old woman with a history of a dysenteric illness and documented Campylobacter infection presented with amoebic psoas and liver abscesses. A review of the literature of the last 20 years did not yield any reports of an amoebic psoas abscess.
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A unique closed abduction-external rotation ankle fracture with a combined medial malleolar fracture and avulsion of the deltoid ligament is presented. Thorough literature search has not revealed a similar case. This report is well documented with an operative photograph, radiographs, and a 20-month followup. A mechanical basis for such an injury pattern is described. The magnitude and complexity of the injuring forces applied to the ankle region in road trauma may lead--as in this presentation--to unusual injury combinations.
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A technique is reported here for the quantitative extraction of live cells from the lung interstitium; it involves the incubation of slices of perfused lung in a mixture containing optimal concentrations of collagenase, DNAse, and fetal calf serum, followed by the simultaneous recovery and fractionation of cells released from the tissue matrix on a six-step discontinuous percoll gradient. Yields in the order of 10(8) viable cells per gram of lung were routinely achieved with tissues from rat, mouse and guinea-pig. Preliminary characterization of these cells has been performed in the rat by histological techniques (Giemsa staining, transmission electron microscopy), cytochemistry (acid phosphatase, esterase, peroxidase), by the capacity to bind monoclonal antibodies directed at lymphocyte surface markers, and by a range of functional tests. The cells comprised, on average, 32% macrophages, 44% lymphocytes (T and B cells and large granular lymphocytes), with small numbers of eosinophils, mast cells and epithelial cells. Transmission electron microscopy revealed minimal ultrastructural damage to extracted cells, with such functions as phagocytosis, FcR activity, mitogen responsiveness, antigen presentation, and NK-cell activity, being readily demonstrable. In addition, these activities segregated into defined areas of the six-step density gradient.
Parechymal cells (PC) were prepared by digestion of perfused, lavaged rat lung in a mixture of collagenase and DNase, and harvested on a discontinuous percoll gradient. The process yielded on average 1.0 X 10(8) viable cells/gram tissue. PC were pulsed with soluble antigen, and tested for their capacity to trigger antigen-specific activation of immune T-cells in vitro, or to replace adherent accessory cells necessary for Concanavalin A (Con A)-induced T-cell proliferation. Unfractionated PC exhibited only minor antigen-presenting cell (APC) activity. However, removal of adherent or FcR-positive cells unmasked substantial APC activity. Subsequent experiments indicated that the majority of the APC banded at the top of the percoll gradient (density less than 1.048 g/ml). The same cell preparations substituted for adherent accessory cells in Con A- activation of T cells, suggesting capacity to secrete soluble factors such as interleukin-1 (IL-1) as well to present antigen. The PC preparation also contained T-cells, which were refractory to Con A stimulation unless endogenous adherent cells were first removed. Collectively, these data suggest the presence of non-adherent, FcR-negative, low density accessory cells in the lung parenchyma, capable of both APC activity and soluble factor production. Their T-cell-activation functions appear to be down regulated by endogenous adherent, FcR-positive cells. It is speculated that the accessory cells in these lung preparations may be dendritic cells, the activity of which is subject to inhibition by macrophages.