Patents by Inventor Paul J. Lawrence

Paul J. Lawrence has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5268146
    Abstract: A dry test panel for the testing of samples such as undiluted bodily fluid specimens is disclosed. The panel contains all reagents and components necessary to achieve a visible indication of the presence or absence of a suspect analyte in the sample, and preferred embodiments contain positive and negative controls as well. The device contains an internal chamber into which the specimen is introduced, and which contains all materials necessary for the reactions which produce a color change which is visible on the outer surface of the device. The materials are positioned in the chamber in such a manner that they are activated only when the chamber is filled with the specimen, and the color indicator is concentrated in a thin lamina immediately adjacent to a light-transmitting wall of the device so that a detectable color change occurs in a short period of time to produce a sensitive and yet fast test.
    Type: Grant
    Filed: March 25, 1992
    Date of Patent: December 7, 1993
    Assignee: Litmus Concepts, Inc.
    Inventors: Paul J. Lawrence, Marian B. Buccafurni, Leah P. Lawrence
  • Patent number: 5068197
    Abstract: An improved method for detecting peroxidatively active materials in a sample is provided, the method incorporating antimalarial drugs such as quinine, quinidine, chloroquine, primaquine, and quinacrine as modulating compounds. In a preferred embodiment, the method is a fecal occult blood test (FOBT), in which a fecal specimen is contacted with a chromogen and a hydroperoxide in the presence of a selected quinoline derivative. The method enables careful modulation of test sensitivity and specificity, and further provides an FOBT in which interference from dietary meat ingestion is substantially eliminated.
    Type: Grant
    Filed: May 17, 1990
    Date of Patent: November 26, 1991
    Assignee: Litmus Concepts, Inc.
    Inventor: Paul J. Lawrence
  • Patent number: 5053342
    Abstract: An improved method for detecting peroxidatively active materials in a sample is provided, the method incorporating antimalarial drugs such as quinine, quinidine, chloroquine, primaquine, and quinacrine as modulating compounds. In a preferred embodiment, the method is a fecal occult blood test (FOBT), in which a fecal specimen is contacted with a chromogen and a hydroperoxide in the presence of a selected quinoline derivative. The method enables careful modulation of test sensitivity and specificity, and further provides an FOBT in which interference from dietary meat ingestion is substantially eliminated.
    Type: Grant
    Filed: May 7, 1990
    Date of Patent: October 1, 1991
    Assignee: Litmus Concepts, Inc.
    Inventor: Paul J. Lawrence
  • Patent number: 4971914
    Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromagen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.
    Type: Grant
    Filed: March 28, 1988
    Date of Patent: November 20, 1990
    Assignee: Litmus Concepts, Inc.
    Inventor: Paul J. Lawrence
  • Patent number: 4942132
    Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromagen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.
    Type: Grant
    Filed: March 28, 1988
    Date of Patent: July 17, 1990
    Assignee: Litmus Concepts, Inc.
    Inventor: Paul J. Lawrence
  • Patent number: 4939097
    Abstract: An improved method for detecting peroxidatively active materials in a sample is provided, the method incorporating antimalarial drugs such as quinine, quinidine, chloroquine, primaquine, and quinacrine as modulating compounds. In a preferred embodiment, the method is a fecal occult blood test (FOBT), in which a fecal specimen is contacted with a chromogen and a hydroperoxide in the presence of a selected quinoline derivative. The method enables careful modulation of test sensitivity and specificity, and further provides an FOBT in which interference from dietary meat ingestion is substantially eliminated.
    Type: Grant
    Filed: December 24, 1987
    Date of Patent: July 3, 1990
    Assignee: Litmus Concepts, Inc.
    Inventor: Paul J. Lawrence
  • Patent number: 4937197
    Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromagen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.
    Type: Grant
    Filed: February 11, 1988
    Date of Patent: June 26, 1990
    Assignee: Litmus Concepts, Inc.
    Inventor: Paul J. Lawrence
  • Patent number: 4820646
    Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromogen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.
    Type: Grant
    Filed: March 28, 1988
    Date of Patent: April 11, 1989
    Assignee: Litmus Concepts, Inc.
    Inventor: Paul J. Lawrence
  • Patent number: 4818702
    Abstract: Fecal occult blood tests of enhanced sensitivity, specificity, and readability are provided by employing (1) a developer or complete reagent solution that uses as a solvent system a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a multi-chromogen comprised of a mixture of guaiac and ABTS. Test results may be further improved by incorporating hemoprotein solubilizing agents, plant peroxidase inhibitors, iron/copper chelating agents, accelerators and buffers in the developer/reagent.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: April 4, 1989
    Assignee: Litmus Concepts, Inc.
    Inventor: Paul J. Lawrence
  • Patent number: 4777143
    Abstract: A method for detecting the presence of carboxylic acids in a specimen is provided. A specimen is contacted with a developing system containing a metal salt reactive with carboxylic acids present in the specimen to form metal-carboxylic acid complexes. Any such complexes are colorimetrically detected by their activity in catalyzing oxidation of a chromogen such as guaiac. The method is useful in detecting intestinal helminth infestation.
    Type: Grant
    Filed: December 12, 1986
    Date of Patent: October 11, 1988
    Assignee: Litmus Concepts Inc.
    Inventors: Neil H. Price, Paul J. Lawrence
  • Patent number: 4615982
    Abstract: Fecal occult blood tests of enhanced sensitivity and specificity are provided by employing (1) a developer composition comprising a solution of a hydroperoxide in a solvent comprising at least about 50% by volume of a solvent for iron protoporphyrins such as dimethyl sulfoxide and/or (2) a solid test matrix comprising a solid support impregnated with a leuco dye and a hemoprotein solubilizing agent. Test results may be further improved by incorporating plant peroxidase inhibitors, iron/copper chelating agents and buffers in the developer and/or test matrix.
    Type: Grant
    Filed: December 11, 1984
    Date of Patent: October 7, 1986
    Inventor: Paul J. Lawrence
  • Patent number: 4486536
    Abstract: A method and novel absorbent substrate for determining the presence of occult blood in gastric fluid. The substrate is acid treated and contains guaiac. The method includes the addition of the gastric fluid to the acid treated guaiac substrate which is developed with a buffered developing solution. Preferably the substrate is an acid treated sheet of absorbent paper and the developing solution is an aqueous buffered solution of hydrogen peroxide.
    Type: Grant
    Filed: August 19, 1982
    Date of Patent: December 4, 1984
    Assignee: Smithkline Diagnostics, Inc.
    Inventors: Josefina T. Baker, Paul J. Lawrence, Charles W. Townsley
  • Patent number: 4382064
    Abstract: Specimen test slides for occult blood having a receiving sheet between a front panel and a rear panel with openings in the front and rear panels and pivotal covers coated with 2,6-di-tert-butyl-p-cresol to cover said openings.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: May 3, 1983
    Assignee: SmithKline Instruments, Inc.
    Inventors: Michael B. Detweiler, Paul J. Lawrence, Charles W. Townsley
  • Patent number: 4365970
    Abstract: An improved specimen test slide having a front panel and a rear panel. The front panel has one or more openings. Sheet means carrying a test reagent underlie each of these openings for reception of a specimen. A hinged cover overlies the openings. The rear panel has flap means opposite said openings which is pivotable to expose the underside of the sheet to permit application of a developing solution. The underside of the sheet which faces the rear panel also has a control area positioned on a portion thereof at some distance from the portions of the sheet underlying the openings of the front panel. The control area contains positive and negative monitors.
    Type: Grant
    Filed: May 1, 1981
    Date of Patent: December 28, 1982
    Assignee: SmithKline Instruments, Inc.
    Inventors: Paul J. Lawrence, Charles W. Townsley
  • Patent number: 4329317
    Abstract: Specimen test slides for occult blood having a receiving sheet between a front panel and a rear panel with openings in the front and rear panels and pivotal covers coated with 2,6-di-tert-butyl-p-cresol to cover said openings.
    Type: Grant
    Filed: January 29, 1981
    Date of Patent: May 11, 1982
    Assignee: Smithkline Instruments, Inc.
    Inventors: Michael B. Detweiler, Paul J. Lawrence, Charles W. Townsley