Abstract: A medical imaging system for detecting ionizing radiation. The system includes one or more pixilated imagers positioned to acquire patient image data and one or more position sensors positioned to acquire patient position data. Once the patient image data and patient position data are acquired, one or more processors operably connected to each of the one or more pixilated imagers and one or more position sensors calculate a three-dimensional mass distribution based on patient image data and patient position data.

Abstract: .beta.-D-Galactosidase conjugates for use in homogeneous immunoassays. .beta.-D-Galactosidase is conjugated with analytes and the resulting conjugates are combined with receptors for the analyte and a sample suspected of containing the analyte. The resulting enzymatic activity is compared to standard assay media for quantitative determination of the analyte.

Abstract: Novel biological assay method for determining the presence of a specific organic material by employing a modified enzyme for amplification. By employing receptors specific for one or a group of materials (hereinafter referred to as "ligands") and binding an enzyme to the ligand or ligand counterfeit to provide an "enzyme-bound-ligand", an extremely sensitive method is provided for assaying for ligands. The receptor when bound to the enzyme-bound-ligand substantially inhibits enzymatic activity, providing for different catalytic efficiencies of enzyme-bound-ligand and enzyme-bound-ligand combined with receptor.The receptor, ligand and enzyme-bound-ligand are combined in an arbitrary order and the effect of the presence of ligand on enzymatic activity determined. Various protocols may be used for assaying for enzymatic activity and relating the result to the amount of ligand present.

Abstract: Novel biological assay method for determining the presence of a specific organic material by employing a modified enzyme for amplification. By employing receptors specific for one or a group of materials (hereinafter referred to as "ligands") and binding an enzyme to the ligand or ligand counterfeit to provide an "enzyme-bound-ligand", an extremely sensitive method is provided for assaying for ligands. The receptor when bound to the enzyme-bound-ligand substantially inhibits enzymatic activity, providing for different catalytic efficiencies of enzyme-bound-ligand and enzyme-bound-ligand combined with receptor.The receptor, ligand and enzyme-bound-ligand are combined in an arbitrary order and the effect of the presence of ligand on enzymatic activity determined. Various protocols may be used for assaying for enzymatic activity and relating the result to the amount of ligand present.

Abstract: Novel biological assay method for determining the presence of a specific organic material by employing a modified enzyme for amplification. By employing receptors specific for one or a group of materials (hereinafter referred to as "ligands") and binding an enzyme to the ligand or ligand counterfeit to provide an "enzyme-bound-ligand", an extremely sensitive method is provided for assaying for ligands. The receptor when bound to the enzyme-bound-ligand substantially inhibits enzymatic activity, providing for different catalytic efficiencies of enzyme-bound-ligand and enzyme-bound-ligand combined with receptor.The receptor, ligand and enzyme-bound-ligand are combined in an arbitrary order and the effect of the presence of ligand on enzymatic activity determined. Various protocols may be used for assaying for enzymatic activity and relating the result to the amount of ligand present.

Abstract: Novel conjugated enzyme compositions are provided for use in homogeneous enzyme immunoassays. A wide variety of compounds, particularly drugs, including drugs of abuse, drugs used in repetitive therapeutic applications, hormones, and the like, are conjugated to malate dehydrogenase. The resulting products have a high turnover rate, so as to provide a high multiplication factor when employed in a homogeneous immunoassay, have long storage lives, and allow for the accurate and sensitive detection of compounds of interest.

Abstract: Novel biological assay method for determining the presence of a specific organic material by employing a modified enzyme for amplification. By employing receptors specific for one or a group of materials (hereinafter referred to as "ligands") and binding an enzyme to the ligand or ligand counterfeit to provide an "enzyme-bound-ligand", an extremely sensitive method is provided for assaying for ligands. The receptor when bound to the enzyme-bound-ligand substantially inhibits enzymatic activity, providing for different catalytic efficiencies of enzyme-bound-ligand and enzyme-bound-ligand combined with receptor.The receptor, ligand and enzyme-bound-ligand are combined in an arbitrary order and the effect of the presence of ligand on enzymatic activity determined. Various protocols may be used for assaying for enzymatic activity and relating the result to the amount of ligand present.

Abstract: A method is provided for the determination of receptors, particularly antibodies, where a polyepitopic reagent is employed, at least one of the epitopes being specific for the receptor of interest. The epitopic sites are situated on the reagent, so that the binding of the receptor of interest to the reagent will sterically hinder binding of receptors other than the receptor of interest.In carrying out the assay, the sample suspected of containing the receptor of interest, the reagent, and a predetermined amount of receptors for the other epitopes are combined. Because of the steric inhibition to the simultaneous binding of the two different receptors, the amount of receptor of interest bound to the reagent will affect the amount of the other receptor which becomes bound to the reagent.

Abstract: Novel biological assay method for determining the presence of a specific organic material by employing a modified enzyme for amplification. By employing receptors specific for one or a group of materials (hereinafter referred to as "ligands") and binding an enzyme to the ligand or ligand counterfeit to provide an "enzyme-bound-ligand", an extremely sensitive method is provided for assaying for ligands. The receptor when bound to the enzyme-bound-ligand substantially inhibits enzymatic activity, providing for different catalytic efficiencies of enzyme-bound-ligand and enzyme-bound-ligand combined with receptor.The receptor, ligand and enzyme-bound-ligand are combined in an arbitrary order and the effect of the presence of ligand on enzymatic activity determined. Various protocols may be used for assaying for enzymatic activity and relating the result to the amount of ligand present.

Abstract: Novel conjugated enzyme compositions are provided for use in homogeneous immunoassays. A wide variety of haptenic compounds, such as drugs of abuse, therapeutic drugs, naturally occurring hormones, and the like, are conjugated to the enzyme lysozyme for use as reagents in homogeneous enzyme immunoassays. From 1 to 5 haptens are conjugated to the enzyme, and the enzyme is substantially inhibited when bound to antibodies bound to the conjugated hapten.

Abstract: Novel compositions are provided for the determination of one or a group of organic materials (hereinafter referred to as "ligands"), where the compositions have a ligand or ligand counterfeit bonded to an enzyme, the conjugate referred to as "enzyme-bound-ligand." Specifically, the ligands are benzdiazocycloheptane drugs, which are conjugated to an enzyme, so that upon binding of a receptor, usually an antibody, the activity of the enzyme changes. Determinations of the benzdiazocycloheptane drugs in a physiological fluid are performed by combining the enzyme conjugate, the physiological fluid and receptor under conditions whereby the amount of receptor bound to the conjugate is related to the amount of the benzdiazocycloheptane drug present in the sample. By metering the enzyme activity of the assay mixture and comparing the result to known standards, the amount of benzdiazocycloheptane drug present in the sample may be determined.

Abstract: Polyiodothyronine conjugates to enzymes are provided which find use in the determination of polyiodothyronine compounds, particularly thyroxine, normally in physiological fluids, such as serum. The enzymes can provide substantial variation in activity when bound to protein receptors for polyiodothyronine as compared to the free or unbound polyiodothyronine conjugated to the enzyme. Various linking groups are provided for linking the polyiodothyronine to the enzyme.

Abstract: Enzyme conjugates are prepared of cardiac glycosides and aglycones for use in homogeneous enzyme immunoassays. The conjugates retain a substantial degree of the original activity of the enzyme and upon binding of receptor to the steroid moiety, a substantial diminution of enzyme activity is obtained. Various linking groups are employed for linking the steroid portion of the molecule to the enzyme, such as non-oxo carbonyl groups.

Abstract: Novel biological assay method for determining the presence enzyme a specific organic material by employing a modified enayme for amplification. By employing receptors specific for one or a group of materials (hereinafter referred to as "ligands") and binding an enzyme to the ligand or ligand counterfeit to provide an "enzyme-bound-ligand", an extremely sensitive method is provided for assaying for ligands. The receptor when bound to the enzyme-bound-ligand substantially inhibits enzymatic activity, providing for different catalytic efficiencies of enzyme-bound-ligand and enzyme-bound-ligand combined with receptor.The receptor, ligand and enzyme-bound-ligand are combined in an arbitrary order and the effect of the presence of ligand on enzymatic activity determined. Various protocols may be used for assaying for enzymatic activity and relating the result to the amount of ligand present.

Abstract: Novel biological assay method for determining the presence of a specific organic material by employing a modified enzyme for amplification. By employing receptors specific for one or a group of material (hereinafter referred to as "ligands") and binding an enzyme to the ligand or ligand counterfeit to provide and "enzyme-bound-ligand", an extremely sensitive method is provided for assaying for ligands. The receptor when bound to the enzyme-bound-ligand substantially inhibits enzymatic activity, providing for different catalytic efficiencies of enzyme-bound-ligand and enzyme-bound-ligand combined with receptor.The receptor, ligand and enzyme-bound-ligand are combined in an arbitrary order and the effect of the presence of ligand on enzymatic activity determined. Various protocols may be used for assaying for enzymatic activity and relating the result to the amount of ligand present.