Nmr quantification of tmao
AssigneeLipoScience, Inc.
InventorsJames D. Otvos, Elias J. Jeyarajah, Justyna E. Wolak-Dinsmore, Thomas M. O'Connell, Dennis W. Bennett, Steven P. Matyus
Life of this patent
Estimating the term…
Abstract
A defined peak region residing between about 3.2 and 3.4 ppm of a proton NMR spectrum of an in vitro biosample is electronically evaluated to determine a level of trimethylamine-N-oxide (“TMAO”). The biosamples may be any suitable biosamples including human serum with a normal biologic range of between about 1-50 μM or urine with a normal biologic range of between about 0-1000 μM.
Claims27
(canceled)
The method of claim 7, further comprising:
- electronically identifying a pH-stable reference peak region in the NMR spectrum of the biosample;
- electronically identifying a defined calibration peak region in the NMR spectrum of the biosample, wherein the calibration peak region has a location that changes based on pH of the biosample;
- and
- electronically calculating a distance between the reference and calibration peak regions;
- then
- electronically determining a location of the TMAO peak for the defined TMAO peak region based on the calculated distance.
The method of claim 7, wherein the biosample is a blood plasma or serum wherein the defined TMAO peak is at about 3.30 ppm.
5-6. (canceled)
A method of determining a measure of TMAO in in vitro biosamples, comprising:
- electronically determining a level of trimethylamine-N-oxide (“TMAO”) of an in vitro biosample using a defined TMAO peak region having a single TMAO peak residing between about 3.2 and 3.4 ppm of a proton NMR spectrum,
- wherein the electronic determination of the level of TMAO is carried out using a defined relationship between a location of a reference peak or peaks and a location of a pH sensitive calibration peak or peaks, and an expected TMAO peak location, wherein a probable actual TMAO peak location is then identified by:
- electronically weighting a region around the expected TMAO peak location with a defined function;
- then
- electronically identifying a highest weighted data point of the weighted region;
- then
- electronically identifying a probable actual TMAO peak location corresponding to location of the highest weighted data point.
12-23. (canceled)
The computer program product of claim 32, further comprising:
- computer readable program code that identifies a pH-stable reference peak region in the NMR spectrum of the biosample;
- computer readable program code that identifies a defined calibration peak region in the NMR spectrum of the biosample;
- computer readable program code that calculates a distance between the reference and calibration peak regions;
- and
- computer readable program code that determines a position of the TMAO peak region based on the calculated reference and calibration peak region distance.
26-31. (canceled)
A computer program product for evaluating in vitro biosamples, the computer program product comprising:
- a non-transitory computer readable storage medium having computer readable program code embodied in the medium, the computer-readable program code comprising:
- computer readable program code that evaluates NMR signal in at least one defined peak region that includes a trimethylamine-N-oxide (TMAO) peak region residing between about 3.2 and 3.4 ppm of a proton NMR spectrum of an in vitro biosample to determine a level of TMAO,
- wherein the computer readable program code that evaluates the TMAO peak region to determine the level of TMAO includes:
- computer readable program code that weights a region around an expected TMAO peak location with a defined function;
- computer readable program code that identifies a highest weighted data point of the weighted region as a probable actual TMAO peak location;
- and
- computer readable program code that applies a curve fitting function or functions to a curve fitting region of about 30 to about 50 data points centered about the identified probable actual TMAO peak location to determine a level of TMAO.
(canceled)
The system of claim 50, wherein the at least one processor is configured to (i) identify a pH-stable reference peak region in the at least one NMR spectrum of the biosample;
- (ii) identify a defined calibration peak region in the at least one NMR spectrum of the biosample;
- (iii) calculate a distance between the reference and calibration peak regions;
- then (iv) determine a location of a single TMAO peak of the defined TMAO peak region based on the calculated distance.
The system of claim 50, wherein a location of the defined TMAO peak region is determined using a defined mathematical relationship that correlates a location of the calibration peak with a location of the TMAO peak, both of which vary according to pH of the biosample, relative to a calculated distance between the calibration peak or peaks and at least one reference peak.
37-40. (canceled)
The system of claim 50, wherein the at least one processor is configured to generate measurements that are substantially linear in a biological range of between about 1-50 μM.
The system of claim 50, wherein the reference peak region is associated with anomeric glucose at about 5.20 ppm, and wherein the calibration peak region is associated with one or more peaks of a citrate multiplet.
43-49. (canceled)
An analysis system, comprising:
- at least one NMR spectrometer for acquiring at least one proton NMR spectrum of an in vitro biosample;
- and
- at least one processor in communication with the at least one NMR spectrometer, the at least one processor configured to determine a level of trimethylamine-N-oxide (“TMAO”) in the biosample using the at least one proton NMR spectrum based on a defined TMAO peak region residing between about 3.2 and 3.4 ppm of the at least one proton NMR spectrum,
- wherein the at least one processor is configured to identify an expected TMAO peak location using a defined relationship between a location of a reference peak or peaks and a location of a pH sensitive calibration peak or peaks, and wherein the at least one processor is configured to identify a probable actual TMAO peak location by (i) weighting a region around the expected TMAO peak location with a defined function;
- then (ii) identify a highest weighted data point of the weighted region as the probable actual TMAO peak location.
Dependencies are inferred from the claim text.