Photoinduced free radicals of visual pigments in solutions mobile at--196 degrees C.
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Alkanes↗
Biomedical subjects
R Sack
Publications and source records attributed to R Sack.
Cryobiochemical analysis of tissue.
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Animals↗
Immunoglobulin deposition on soft contact lenses: relationship to hydrogel structure and mode of use and giant papillary conjunctivitis.
Since the IgG to IgA ratio in the tear film increases dramatically during inflammation, the ratio of immunoglobulins deposited on the soft contact lens surface should provide some indication of biocompatibility of the hydrogel. To study this premise, 60 soft contact lenses of low and high water content and ionic and non-ionic compositions were recovered after their useful lifespan from asymptomatic lens wearers and those experiencing active giant papillary conjunctivitis (GPC). Lenses were exhaustively extracted with saline to remove loosely bound immunoglobulins, dissected, and qualitatively assayed by means of chromogenic horse radish peroxidase-linked antibody probes for tightly bound IgG and IgA. The intensity of reaction was scored visually in a random, masked fashion by two independent observers using a standardized scale. The results reveal a consistent, although not statistically significant, increase in IgG to IgA deposition on the pathological lens population as compared to normals. This change may be reflective of an immune specific lens response and/or the enhanced titer of tear IgG resulting from the inflammatory process present with GPC. Deposition correlated more strikingly with two other linked parameters: hydrogel structure and mode of use. A marked increase in immunoglobulin deposition and enhanced IgG to IgA ratio (P less than 0.001) was common to high water content lenses (especially of non-ionic composition) used on an extended wear basis, when contrasted with low water content lenses used on a daily wear basis. It is thus hypothesized that use of high water content lenses on an extended wear basis leads to a greater degree of inflammatory and/or immune stress.
Biocompatible Materials↗