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US5384239A
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Method for analyzing the glycation of hemoglobin
Assignee: Chronomed Inc
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Filing: 1993-01-21
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Granted: 1995-01-24
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Expires: 2013-01-21
Abstract
Abstract As red blood cells age, their hemoglobin is progressively glycosylated. This invention relates to analyzing the history of blood sugar metabolism over a period of several months by taking a blood sample, separating the cells into age-ordered cohorts, determining glycohemoglobin levels in the cells of each cohort, and correlating glycohemoglobin levels with red blood cell age, while correcting for the reversibility of the Amadori rearrangement.
Inventors
- 👤 Alexander Saunders
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:40
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/66; G01N33/72; G01N33/721; G01N33/723
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
196 words
A method of determining an individual history of blood sugar control which comprises: (a) taking a sample of red blood cells from the individual, wherein over the life of the red blood cells hemoglobin has been glycosylated to form a glycohemolobin, said reaction being an Amadori rearrangement, which is slowly reversible; (b) separating the red blood cells according to age into a plurality of cohorts, and determining the average age of the red blood cells in each cohort, the average age differing from cohort-to-cohort; (c) measuring the average glycohemoglobin levels of said red blood cells on a cohort-by-cohort basis, and correlating said average glycohemoglobin level with said average age for each cohort, while correcting for the reversibility of the Amadori rearrangement, so as to obtain a history of the individual's blood sugar levels over the lifespan of said red blood cells; and (d) examining said history for trends indicative of changes in blood sugar control; wherein the correction is made by applying a transform of the form ##EQU2## where y is the untransformed mean glycohemoglobin level for the cohort, a and b are constants, e is the base of the natural logarithm and t is time.
Claim 2
Independent Claim
196 words
A method of determining an individual history of blood sugar control which comprises: (a) taking a sample of red blood cells from the individual, wherein over the life of the red blood cells hemoglobin has been glycosylated to form a glycohemolobin, said reaction being an Amadori rearrangement, which is slowly reversible; (b) separating the red blood cells according to age into a plurality of cohorts, and determining the average age of the red blood cells in each cohort, the average age differing from cohort-to-cohort; (c) measuring the average glycohemoglobin levels of said red blood cells on a cohort-by-cohort basis, and correlating said average glycohemoglobin level with said average age for each cohort, while correcting for the reversibility of the Amadori rearrangement, so as to obtain a history of the individual's blood sugar levels over the lifespan of said red blood cells; and (d) examining said history for trends indicative of changes in blood sugar control; wherein the correction is made by applying a transform of the form ##EQU2## where y is the untransformed mean glycohemoglobin level for the cohort, a and b are constants, e is the base of the natural logarithm and t is time.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein the sample is separated into between 8 and 20 age cohorts.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein the mean pyruvate kinase level is determined for each cohort.
Claim 5
Dependent Claim
50 words
The method of claim 1 wherein the Amadori rearrangement results in the formation of an adduct of hemoglobin with a sugar selected from the group consisting of fructosamine, 5-deoxy-xylulose-1-phosphate, galactulose and fructose-6-phosphate and the level of said adduct in the sampled red blood cells is determined on a cohort-by-cohort basis.
References Cited (Backward Citations)
US4835097A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-23 | 1998-07-25 | 1999-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-23 | 2002-07-25 | 2003-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-23 | 2006-07-25 | 2007-01-24 | $7700.00 | Window Closed / Lapsed |