Biomedical subjects
Publications and source records attributed to E Lantz.
We report an experiment of type 2 parametric image amplification in a phase sensitive configuration. In the spatial frequency domain, the parametric gain corresponds to amplification or deamplification, depending on the relative phase of the input image with respect to the pump wave and on the spatial frequencies of the input image.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The nature of corneal and conjunctival plasminogen activators (PAs) from human and rabbit eyes was examined in tissue culture. The fibrinolytic activity of culture fluid from human corneas was low, roughly one-eighth of that of rabbits. The main activity was found to be of the urokinase (UK) type, as demonstrated by crossed immunoelectrophoresis against alpha 2-antiplasmin after incubation with mixed plasma. The fibrinolytic activity of culture fluid from human conjunctival tissue was higher and a mixed secretion of tissue type (tPA) and UK activator was demonstrated. These activators were separated by affinity chromatography against Sepharose-immobilized antibodies against tPA. Fibrinolytic activity in tears was quenched by antibodies against tPA but not by the use of anti-UK antibodies. Thus, in man, tear fibrinolytic activity may depend primarily on a release of PAs from conjunctival tissue.
The authors studied the release of fibrinolytic activators from in vitro cultures of human and animal cornea with the following main findings: (1) the epithelium is the main activator source; (2) the addition of tripeptide, salicylate, chloroquine and phorbolester to the culture medium increases the fibrinolytic activity of the cultures; (3) corticosteroids depress the fibrinolytic activity; (4) explants of human conjunctiva also release fibrinolytic activators. The pathophysiological role of this activator is unknown. Hypothetically, besides preventing fibrin deposition on the surface of the eye, this activator may also stimulate leucocyte migration, activate procollagenase, protect the endothelial pump, and regulate vascular permeability and angiogenesis in the cornea.
Explore the source record for details and available documents.
Rabbit corneas cultured in vitro in chemically defined media continuously released fibrinolytic agents. Such a substance was an activator of plasminogen and was released largely from the epithelium. Addition of prednisolone did not modify fibrinolytic activity, while death of the explants was followed by cessation of fibrinolysis, a finding suggesting synthesis of the activator during culture.
Explore the source record for details and available documents.