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Biomedical subjects

I J Turner

Publications and source records attributed to I J Turner.

4 recordsLinked to original sources

Computer-aided area measurement of ocular images.

Using a combination of computer-aided measurement techniques and fundus camera images, the area of regions of interest on the fundus can be measured. If these area measurements are corrected for the magnification effects of the patient's visual system, and the fundus camera optics, an estimate of the true anatomical size of the measured object can be determined in physical units. While the results of measuring models indicate a maximum error of 6% for the system, the results of clinical trials demonstrate an average error of 10% for well-defined areas of interest, with increasing error of up to 30% for poorly defined areas of interest.

Adult↗

Video and digital fluorescein angiography.

A video recording system, which provides real-time imaging and instant reporting of retinal fluorescein angiograms, with improved patient comfort, is described. Digital image-processing methods can be applied to video angiograms to improve image quality, quantitate retinal blood flow, measure areas, improve storage and access, and send images via phone lines or other electronic communication channels. Video image quality is somewhat inferior to conventional photographic techniques, but is more than adequate for diagnostic interpretation.

Computer Communication Networks↗

Single radial hemolysis test for quantitation of complement-fixing antibodies to non-hemagglutinating viruses.

A single radial hemolysis test, which overcomes many of the problems of conventional complement fixation tests, was developed for the quantitation of virus complement-fixing antibodies. The test procedure utilized staphylococcal protein A-coated sheep erythrocytes immobilized in agarose into which antigen was incorporated. Undiluted heat-inactivated serum samples were allowed to diffuse radially from wells punched in the agarose. Protein A served to concentrate the subsequent antigen-antibody reaction on the surface of the erythrocytes. Zones of hemolysis were developed by flooding with complement. With adenovirus as a model, basic test parameters were defined, and optimum reagent concentrations and diffusion conditions were determined. A positive linear relationship was found to exist between zone diameter and increasing log concentration of specific antiserum. No correlation was found between zone diameter and total concentration of immunoglobulin G in test sera. Sera rendered anticomplementary by the addition of carrageenan produced hemolytic zones equal to diameter to those observed with untreated sera. Seventy-seven human sera with known complement fixation titers were tested by this method. Good correlation (r = 0.74) between the complement fixation test and single radial hemolysis was observed. This test was highly reproducible and more sensitive than the conventional complement fixation test.

Adenovirus Infections, Human↗