Abstract: Novel assay kits and methods are described for the detection and determination of the severity of disease conditions associated with elevated levels of aspartate aminotransferase (AST). The AST levels are determined by reaction of the AST with cysteine sulfinic acid (CSA) substrate in the presence of a sulfite-reactive dye compound that is substantially nonreactive with AST or CSA, such as a triarylmethine dye. Sulfite ion formed by the reaction of AST with CSA causes a calorimetric indication of AST that can be related to a predetermined stage of disease.

Abstract: The present invention provides for light fatigue resistant photochromic compositions including a unique combination of hindered aminoether light stabilizer ("HAELS") compounds to extend the usable lifetime of naphthopyran photochromic compositions and articles. Additionally, light stabilizer compounds and hydroxyphenyl benzotriazole UV absorbers have a synergistic effect in extending the usable lifetime of photochromic compositions and articles. Specifically, certain tertiary and secondary amine HALS compounds in combination with hydroxyphenyl benzotriazole UV absorbers extend the usable lifetime of spiro-indolino-oxazine photochromic compositions and articles. Similarly, aminoether HAELS compounds in combination with hydroxyphenyl benzotriazole UV absorbers further extend the usable lifetime of the naphthopyran photochromic compositions and articles.

Abstract: Photochemical systems for the direct visualization of exposure to ultraviolet radiation that effect visible color changes involving a process in which a photoacid is formed upon irradiation of a nitro-substituted aromatic aldehyde with ultraviolet light and wherein proton transfer to a dye causes the dye to undergo a visible color change. The system undergoes such color change to an extent directly proportional to the cumulative amount of ultraviolet incident thereupon.

Abstract: Photochromic ink comprising a spiroheterocycle or metal dithiozonate photochromic dye.

Abstract: Method for determining the presence of an aminotransferase (AT.sub.1), other than aspartate aminotransferase (AST), in a biological sample. The method includes contacting the sample with an amino donor substrate for AT.sub.1, an amino acceptor substrate for AT.sub.1, cysteine sulfinic acid (CSA) in excess, a second aminotransferase (AT.sub.2), different from AT.sub.1, in excess, and an indicator for the presence of sulfite ions, under conditions in which the concentration of said AT.sub.1 can be determined by the amount of the indicator which forms a detectable signal.

Abstract: A phototranschromic ink suitable for use in a printing machine, including a water soluble, inert, nonionic polymeric resin carrier base having film forming properties, a photo acid or photo base progenitor which releases or takes up protons upon exposure to light, a pH sensitive dye which changes color in response to a change in proton levels, a water compatible non-ionic wetting agent, a water compatible non-ionic thickening agent, a neutral water soluble flow aid; wherein said ink changes color upon exposure to ultraviolet radiation and is of suitable consistency for use in a printing machine.

Abstract: Photochemical systems for the direct visualization of exposure to ultraviolet radiation that effect visible color changes involving a process in which a photoacid is formed upon irradiation of a nitro-substituted aromatic aldehyde with ultraviolet light and wherein proton transfer to a dye causes the dye to undergo a visible color change. The system undergoes such color change to an extent directly proportional to the cumulative amount of ultraviolet incident thereupon.

Abstract: Disclosed are methods for determining the presence of periodontal disease in mammals. The methods include the steps of (1) sampling gingival crevicular fluid, (2) assaying the crevicular fluid sample by colorimetric or other means to determine levels of alanine aminotransferase present, and (3) correlating the levels of L-alanine aminotransferase present in the crevicular fluid sample with a standard which is indicative of the presence of periodontal disease.

Abstract: Disclosed are improvements in methods for determining the presence of suprathreshold amounts of aspartate aminotransferase in an oral fluid sample by (1) incubation of aspartate aminotransferase substrate materials in a first reaction mixture with the sample to form a first reaction product and (2) detection of reaction product therein by incubation with an indicator substance in a second reaction mixture wherein a second colored reaction product is formed.